Poor appearance due to sloppy work or downright safety-endangering botched jobs can also happen with professionals. There are more than enough examples here in the forum. Therefore, honestly, you don't have much choice but to deal with the topic. And even high-quality execution by a professional does not guarantee in the end that everything will look good. Sometimes you want something different than what actually appeals to you. Spending more time on the subject increases the chance that you are right. For me, for example, it is hard to imagine that the appearance of chest-high L-stones actually pleases even remotely as many people as install them. Or do they always only show them to the neighbor who then has to deal with them?
Be that as it may, I accept the argument "I might not like it," but to derive "this is all much too difficult and complicated" right away, that's too much for me. There is a point at which I wouldn’t do it anymore, and that is, for example, at 1.5m walls. But in property planning, you can also look at whether you can avoid something like that by working with the terrain. I wouldn’t want to impose that on myself or the neighbor.
As I said, it always depends on the terrain.
A courtyard with a 40cm slope over, for example, 6-7 meters with different heights in the driveway area, house entrance area, is fundamentally not easy to work on. You can acquire as much knowledge as you want, it is simply difficult!
Pouring concrete neatly, setting stones is definitely not easy, especially with a correspondingly UNEVEN terrain.
Yes, you are quite right that botched jobs can happen anywhere.
The only difference is this: If something doesn't suit me in the way it was executed by a professional, I have a basis to have it improved, or I simply don't pay the bill as long as it doesn’t look the way I envision it.
For me, this definitely makes a difference... Not everyone dares to take on such work!
My tip: Try to see if you can get the prices lowered by helping out! Bring 2-3 people to the construction site - mostly act as laborers and save some costs that way. It definitely makes sense to have someone on site who has PRACTICAL knowledge.
We also tried to do some things ourselves - we mostly succeeded - but knowledge in theory just looks so much different than in practice.
And if your limit is at 1.5-meter walls, for others it might be reached much earlier?
For a colleague of mine, the limit is already reached when assembling a chest of drawers.