Repairing parquet: Is it wood?

A clear recommendation, as I had hoped for, does not seem to emerge here. Perhaps it was naive to hope for that given the many possibilities.

??? Maybe read all the answers again. :D

Since the HBF no longer offers an introduction thread, you might want to write a small paragraph about what kind of house you bought and that you would like to renovate everything yourself at low cost. Feel free to include photos as well. The users then tend to be a bit more creative and interested. There are some threads here where users present their projects, which then become lively with upcoming questions and many can help. Out of the blue, fewer tips come than with an active construction diary.

????
Maybe read all the answers again. :D

Please don’t misunderstand! I find your last hint especially very important. But other hints tended more towards sanding. So now there are already two directions again and I don’t know how to decide. Before your post, I was sure it should be tried to sand it down. Now I have another "problem" I need to think about. Actually, I thought someone would tell me which grit I should use and I could get started... ;)

Since the HBF no longer offers an introduction thread, you might want to write a short paragraph about the house you bought and that you’d like to renovate everything yourself cost-effectively. Feel free to add photos as well. The users then become a bit more creative and interested. There are some threads here where users present their project, which then come alive with the upcoming questions and many can help. You get fewer tips out of the blue than with a lively construction diary.

I will consider it. Sorry if all this comes across as somewhat impersonal or even ungrateful. I am currently under great pressure to somehow plan the most important things by move-in, partly do the work myself or otherwise struggle with craftsmen… I’m probably not the only one who’s like that… but whether I’ll still have the leisure to keep a diary here, that I’m not sure about.

I have already learned quite a bit again through the answers here and I really appreciate that. Unfortunately, the floor still looks the same as on January 3rd and a few gray hairs have come along.

Then I have one more question on the topic "sanding by hand with fine paper and treating with Osmo hardwax oil": Could I also do that with a small hand machine? How fine? 100? 120? Even finer? When we talk about the oil, do we mean Osmo Hardwax Oil Original?

I am fully aware that there is no certainty in this and a remote diagnosis is difficult. But if I have to guess, that’s certainly no better than an educated guess from someone who hopefully has some experience and expertise compared to me.

Oops, links here lead to disqualification.

oops, links lead to exclusion here.

Thanks for the tip. I have edited it out.

There are always several options, and these also depend on your possibilities/wishes.
My approach would be:
Which room is it, how/for what is it used?
What does the floor as a whole look like – are there many pieces of furniture on it, rugs?
What are MY craft skills in this regard?
Financial aspect?
Is the room being renovated as a whole, meaning wallpaper, ceilings, etc.?
If this were not my absolute "showroom," I would first try the easier approach without the big/complex action. If the floor is cleaned and, depending on the product, possibly lightly sanded by hand or machine and then waxed/oiled, it will look great in my opinion. I know a tiler who had even poured gravel on the wooden floor in his showroom for a few weeks so that people could walk on it. Afterwards, it was cleaned and the rustic look sealed with oil/wax. A wooden floor visually forgives so much. We had a very old wooden floor in an old villa, a few scratches, a few gaps... great.
I definitely did not want to unsettle you, but back then I was also told, "just" sand with the big machine, the rest with a hand sander, and you’re done. By now, I am more confident in craftsmanship, yet I still wouldn’t want to do it because you quickly sand in bigger scratches than you had before. Of course, it was also because I wanted to remove 2mm from my 30mm solid wood planks and at first worked with coarser sandpaper.
You mention current stress, hecticness, etc., which is all the more reason to try the simpler version first because I see no reason why it shouldn’t work. In the worst case, buy a small tin and try it out.
For the floor immediately after installation, we used hard wax oil Original silk matt back then. Now there is also rapid for faster processing as well as colored variants. Since you don’t know how the current floor will absorb the color pigments, I would be more cautious there, although... I would be... unfortunately... brave.
When renovating, we wanted a different color and decided on machine sanding based on recommendation... with the well-known miserable outcome, as the colored glaze from décor wax showed the uneven sanding. The rescue was then opaque décor wax, which was totally easy to apply and held up until we moved out after another ten years (despite having a dog) and we always liked it (it’s probably still in there today). #Over the years we, for example, painted our former country house doors with opaque décor wax, and our formerly maize-yellow window frames with grey décor wax.
If it doesn’t work out, you can still sand later.
This is my opinion. That’s how I would do it, and don’t worry, I like to have things looking nice at home.
Looking forward to seeing how you do it... let us know.
So – hopefully you feel more confident again :D