When I got my current dog, she was terrified of linoleum floors,
doorways, and stairways. People thought I was babying the dog by
feeding her in the dining room, but they didn't see how horrible it was
for her to deal with linoleum. If you put her on it, even a step from
the rug, she would go stiff and tremble. There is no way she could
learn anything or deal with it. She simply couldn't cope with that
fear.

We fed her in the dining room on the rug, and we set up a new water
bowl there as well. people said she would get over it if we showed her
the food, but she would have starved to death if food meant crossing
the linoleum.

Why stress them so badly if we can solve it by moving the needed item
away from the fear?  She did eventually master those things. After a
few months of carrying her in and out to do bathroom duty, she started
to relax, and we were
slowly able to work with her. But it took months, and a lot of
patience. Only after she had mastered going in and out across the
linoleum floro did we even attempt to bring her toward the kitchen. And
we used a small rug so that she had a safe place. I've had her 9 years,
and she does linoleum fine now. She still backs out of the kitchen
instead of turning and going forward. No idea why.

To deal with a fear like this, you have to have a lot of patience, and
you can't even begin to have the cat do something near the scary object
until you can successfully hold the cat near it with no reaction. With
Jenny, I could feel her muscles stiffen and her heart race EVERY time
we went near linoleum, a doorway, or stairway. It was terror for her.
If life for a dog didn't involve going outside multiple times a day or
up and down to my bedroom, I would not have even worked on this fear.
As it is, I just carried her for months because that was the only way
to get things done.

There is no requirement for a cat to use the litter box in the
bathroom. And kitty litter issues are the worst if you start up a
problem.  I wouldn't even bother to put a box where a cat isn't happy
to go normally. They need a secure spot.

I keep my main litter box in my bedroom. Not near my bed, but out of
the way with a small privacy door in front in of it. I scoop it every
day, so it only smells bad if somebody is not feeling well, and then
the smell is a good sign that I need to pay attention.