My Mum had one of those seats, it swung out over the side of the bath then back and lowered. She loved it, the only problem I had with it was cleaning underneath it.
I had to lift it out to have a bath, a few years ago now, and it was always disgusting, a lot of cleaning.
Her carers were not allowed to lift it out.
In the care home now she has a shower everyday, and is always complaining that she has not had a bath, to the extent that one of my Cousins arranged a meeting with the home manager as she was so upset.
She had seldom had a shower and hates them.