Interior doors - Snap locks & latches made of plastic!?

doesn't matter at all. Of course, titanium would be more durable. So what.

Well, then this seems to be the 'state of the art'. Inner peace is restored. I have only noticed that the handles are easier to operate (it is unusual, as we have very stiff handle sets here in the apartment) also the WC rosette for locking feels like at a school toilet. Possibly readjustment is sufficient here.

also the toilet seat cover for locking feels like being in a school bathroom.

We have never used it in 7 years. I think it's stylish :D

We currently have self-selected door handle sets from the hardware store here, even for noticeably little money, and they work flawlessly. They work for you too, that is the point. The mental connection to the school toilet is not universal, I think it is right that you can lock this door. Better or different is always possible - but of course also more expensive.

We have never used it in 7 years. I think it looks stylish :D

I use it regularly. Until recently, with 3 women in the house, it was not a bad idea at all. The plastic latches are cheaper, but also quieter when the door is simply slammed shut (which you don't do, but oh well...)

We have never used them in 7 years. I think it's stylish :D

We also have them in the house, never before.

With small children, it really has advantages, because then you have lockable toilets (at least in the guest toilet most will probably appreciate that) without the risk of a child locking themselves in unreachable.
Our eldest once locked herself in the bedroom, we didn’t put the key high up there, and then it gets exciting... She stayed calm, the parents mostly too :p, so she was able to free herself after a few attempts. Otherwise, the door would have had to go.