and not place the bathtub just like that in front of the now very large , so that I can clean it without having to climb into the bathtub?
But you had that in your plan too! At least something similar with a huge platform behind the tub, which almost minimizes the sense of airiness that you want to achieve with a freestanding tub. And you didn’t draw in a freestanding tub either.
How do I fit the toilet and bidet somewhere else?
Why do you want to put those parts somewhere else? They are perfect there, aren’t they? In your sketch they had the eyecatcher spot: the beautiful slanted wall, which should be used for something better in this bathroom than for the toilet/bidet?!
but I don’t like the suggested bathroom solution and I don’t see any really good alternative.
It is better! You don’t like it because you are attached to your tinkering. You fell in love with it because you worked on it and looked at it countless times.
I am thankful for any idea.
I’m happy to try. But actually, I think you’re just being stubborn. That’s okay. But you should realize it and look at the plans very neutrally again. Keep in mind that the shower in your design offers no privacy at all. If you move in with a partner, that’s fine. But between mother and son, you should really pay more attention to something like that. Your mother can easily put a stool in that shower.
I’m attaching a picture of the plan
I thought it was about the whole apartment. I’d be interested. P.S. What do you mean by floor-to-ceiling windows in the bathroom and what do you mean by a freestanding tub?