Being disabled myself, most definitely keep the bathroom!
Altro flooring is the one they put don in wet rooms etc in hospitals, and I hate it! I've slipped on it a few times now and do not think it is non-slip at all, really nothing is when soap is involved. It is an absolute pain to keep clean as it's sort of 'griity' too.
You can get other anti-slip floors which may be cheaper. If you are ok currently, why not get a shower tray that will keep the water at bay, then if you were to become disabled you may be eligible to have a Disabled Facilities Grant to sort it out. Also, have a look at your council's website - mine do a loan scheme for repair and maintenance for homeowners called Lendology, your council may have similar? Sadly here you have to have been in residence for 5 years before you can apply.
I am eligible for a DFG as poor and disabled, but, as you rightly say you have little say in it. Here they wanted to remove my bath, install Altro flooring (yuk) and make a wet-room, with a stairlift to access it. Fair enough, BUT my bathroom is fully tiled top to bottom in large blue/green tiles. It isn't the prettiest and not my choice but it's fine. What they would do however is remove the bath, and replace the large tiles with small white ones, which would look horrific! I have 15 of these large tiles spare, so |I said, if they could do me a white 'shower' in the corner, and use my tiles to fill in the remaining space where the bath came out I would go for that, but no, they can't do that, so I've refused it and will continue to strip wash in the kitchen which I've done for the past 2 years.
What I really NEED is a downstairs loo, but that's another long complicated story ...