Not sure in which age-segments, but it's a pity because it used to be an important social activity for the elderly.
It's not more important than canasta. My grandmother played bridge. My mother played canasta. I play Set. It's just a game.
Apart from the over-lengthy process of learning enough of a system to actually play, Bridge is a fabulous game, and one which is best where there are decent-sized clubs of competent people to play with/against. That's fine for now, at least in bigger places in England, but most of the feeder routes to these clubs have dried up: weekly kitchen table cards is fairly rare, it's not played in schools, and nearly all the university clubs have gone. We run decent teaching sessions but in most places that's not enough to keep up with current players' deaths. Sic transit gloria mundi.