It's not only service charges. Some of them are really unpleasant places for "younger" active older people. The thing is that people who moved in to them when built say 20-30 years ago, and were fit/active etc at that time are now still there, now infirm, some with dementia setting in, etc., and "fit/healthy" 60 year olds don't want to live with them.
OH and I have been looking (aged 60) as we want to downsize and have a small flat so that we can travel etc without having to deal with house repairs, gardening etc. In theory an over 55 block suits us. But, good God, some of them are grim, more like old folks homes, corridors smelling of wee, random elderly people walking around looking lost, etc. Likewise the flats themselves are often in need of a complete makeover despite being only 20-30 years old, i.e. complete new kitchens and bathrooms, redecoration, new carpets throughout etc as a minimum. Yet the owners (or their descendants) still expect top whack for them, despite literally nothing being done in decades such as cleaning, decorating, replacing damaged carpets or damaged kitchen units/appliances.
We're now really only looking at new complexes, which are mostly McCarthy & Stone, and yes, we know exactly what we are getting into, i.e. potential loss of value, high service/management charges, etc., but they're just a lot nicer and currently occupied mostly by younger "old" people who are still fit and healthy, and yes, I know it will be different in 20 years time as the occupants all get older.
Just putting a different point of view that it's not all about management charges that the older blocks aren't popular. Older people wanting to move are more likely to be newly retired etc and they don't want to live in "old folks' homes" alongside those who are now 80 or 90+. The age range is simply too wide. There's one hell of a difference between a typical 55 year old and a typical 80 year old.