Construction costs are currently skyrocketing

That's exactly right. And there are a lot of things that are simple and only cost muscle power and maybe a bit of disposal. Especially in demolition. I wouldn’t install a roof window myself, wouldn’t build a dormer, generally wouldn’t go on the roof. Not proper electrical work, no built-in water pipes. Things like that. But there are many things you can really do well yourself and save a lot of money. You have to be willing to sacrifice time, of course. The work doesn’t do itself.

Sure. You should stay away from those kinds of things.
But installing an interior door yourself is really no rocket science. Someone showed me the first one (which turned out to be a bit crooked, I should have just done it myself from the start) and on Monday, alone with just wedges and 3 cut-to-length timber beams, I managed to install 3 doors... the only thing slowing me down was the fact that I only had 3 timber beams and the foam takes 1 to 2 hours until it really sets without pushing.

A professional probably charges a flat rate of about 50-80 EUR per door installation. "Earning" 150-240 EUR in one day...

Sure, if you earn 35 EUR net, you can probably afford the professional at 70 EUR/hour. But hardly anyone earns that much, especially not in the typical age of a builder, namely early to mid 30s.
I think I don’t earn badly and get a good 20 EUR net/hour. Plus allowances, expenses, travel times, etc.
That means for the 70 EUR that the floor layer charges, I work just under 3.5 hours.

I’d rather do it myself, in the last room I was already significantly faster than at the start.

It probably always depends on the person, the expertise, the expectation, and the skill. For me, it depends on what the work is for. For example, we are planning to tile our garage interior ourselves. My mother said she can help/guide, she has done something like this before. I never have, but in the garage it is not so important to me that it turns out perfect.

We also do quite a bit ourselves, and additionally have relatives who are skilled craftsmen. But there are things where I tell myself, it’s not called a vocational training for nothing, and you don’t become a master for nothing either…

We started masonry work on the upper floor today... Work on the ground floor began last Monday... so 6.5 days for one floor including concrete pouring and 1 day for electricians/ventilation to pull empty conduits. 2 masons from the company and 2 helpers from us – you don’t need to pay anyone €60/net for stone cutting or mixing adhesive, it works out in a similar time like this... I still get "homework" every evening from the boss which I can also do in the evenings as a non-construction worker... But I am currently at the construction site between 9 and 14 hours a day... But the saved amount is quite substantial!

I think you also make the mistake of believing that craftsmen always do professional and above all perfect work. My neighbors had their interior doors installed... many crooked. The neighbor opposite wanted a special Italian plaster technique, the professional said "Of course we can do that"... in the end, he knocked it down again and did it himself because the "professional" simply couldn't do it and also didn't come for a correction.

Tiles... our tiler immediately handed us a sheet showing how much overhang is allowed... and fully used that allowance. Well, I'm not picky, I want to live in it, it's not a tile exhibition... but it is far from perfect.

The bricklayers messed up a rough construction measurement for the door. I only noticed it when I wanted to install the frame. Then I spent an hour rasping Ytong...

My buddy is a kitchen builder, he smeared two nice new white walls and the joint between two panels doesn't fit 100%...

The civil engineers set my cistern a bit too high...

The plumber didn't lay the insulation on the roof properly again, drywall boards had to be replaced due to mold...

When you do something for yourself, you put in more effort. But you should stop after 8 hours, after 6 during strenuous work. Because, indeed, the professional has the advantage that he can still go on after 10 hours... I lose a lot of strength after 6 hours and then start making mistakes because I no longer work with control.

But admittedly... I also enjoy it. I like working with the miter saw, cordless screwdriver, and hammer once in a while as a change from working on the computer.

I think you’re also making the mistake of believing that craftsmen always deliver professional and above all perfect work. My neighbors had the interior doors installed... many crooked. The neighbor opposite wanted a special Italian plastering technique, the pro said "Sure, we can do that"... in the end he knocked it down again and did it himself, because the "pro" simply couldn’t do it and also didn’t come back to fix it.

Tiles... our tiler handed us a sheet right away showing how much overhang is allowed... and fully used it. Well, I’m not picky, I want to live in it, it’s not a tile exhibition... but it’s far from perfect.

The bricklayers messed up the rough opening measurements for the door. I only noticed when I wanted to install the frame. Then I spent an hour there with the Ytong rasp.

My buddy is a kitchen builder, he smeared on two nice new white walls and the joint between two panels doesn’t fit 100%...

The civil engineers set my cistern a bit too high...

The installer didn’t lay the insulation on the roof properly again, drywall panels had to be replaced due to mold...

When you do something for yourself, you put more effort into it. But you should stop after 8 hours, after 6 hours for strenuous work. Because, indeed, the pro has the advantage that he can still go after 10 hours... I get really worn out after 6 hours and then start making mistakes because I no longer work in a controlled way.

But admittedly... I also enjoy it. I like working with a miter saw, cordless screwdriver and hammer every now and then... as a counterbalance to working on the computer.

I think you’re also making the mistake of believing that craftsmen always deliver professional and above all perfect work. My neighbors had the interior doors installed... many crooked. The neighbor opposite wanted a special Italian plastering technique, the pro said "Sure, we can do that"... in the end he knocked it down again and did it himself, because the "pro" simply couldn’t do it and also didn’t come back to fix it.

Tiles... our tiler handed us a sheet right away showing how much overhang is allowed... and fully used it. Well, I’m not picky, I want to live in it, it’s not a tile exhibition... but it’s far from perfect.

The bricklayers messed up the rough opening measurements for the door. I only noticed when I wanted to install the frame. Then I spent an hour there with the Ytong rasp.

My buddy is a kitchen builder, he smeared on two nice new white walls and the joint between two panels doesn’t fit 100%...

The civil engineers set my cistern a bit too high...

The installer didn’t lay the insulation on the roof properly again, drywall panels had to be replaced due to mold...

When you do something for yourself, you put more effort into it. But you should stop after 8 hours, after 6 hours for strenuous work. Because, indeed, the pro has the advantage that he can still go after 10 hours... I get really worn out after 6 hours and then start making mistakes because I no longer work in a controlled way.

But admittedly... I also enjoy it. I like working with a miter saw, cordless screwdriver and hammer every now and then... as a counterbalance to working on the computer.

I agree 100%. Only with the garden I had no more energy, wanted to live again instead of working. There’s still plenty to do after that anyway, you’re never really finished. But I love tiling.