In LA there are tons of "co-living" spaces where they're basically renting out bedrooms for $2500-$4000 a month! It's the similar to living with roommates except each roommate has their own lease and you have no choice in who becomes your roommate.
I don't know any actual stats, only that in searching for an apartment they came up a lot in searches and I assumed it was partly to make more money (a 3br apartment with 3 people paying $3k each is $9k vs renting the whole apartment for $6k-7k)
But, also, rent in general is too damn high and it's lowers the price "for some definition of lower".