Typically an elderly person will own a home or will have assistance from the council for accomodation. Don’t forget about fuel allowance, free travel, medical cards, etc.
But often elderly people tend to be savers, so they don’t actually live on the full amount they get. And that’s a contributory pension, not everyone gets even that. The invalidity pension is quite a bit less than that. And somebody who’s retired due to illness won’t necessarily own their own home. They might have been in their 30’s when they retired.