My two are in late 20s, and both left home when they went to university and stayed near their university cities, so have rented all along. Their rents for modest accommodation are ridiculous, so it is very difficult for them to save enough for a deposit on a house, although both want to buy, and both are engaged to be married.
I blame the sale of council houses for crowding the rental market. If they had been sold at market value and the money used to buy more local authority houses, there would be fewer people needing to line the pockets of private landlords, and rents would be more affordable.