> As a grown adult, having roommates is not really an acceptable situation.

I know plenty of grown adults that have roomates, because they prefer the quality of accommodations they can afford that way to what they would be able to afford without them. (And not even in places with Bay Area-level high cost of housing.)

If it is unacceptable to you, that's fine, but don't pretend it has something to do with being "a grown adult".

What do you count as an adult? I was the weird one by having my own place. Every 'adult' I know had roommates until they found an SO and moved in together and/or got married. These people all made enough money to live alone, but preferred spending money on other things. I also do not live in a super expensive place. A 1br apt. goes for ~1200 in the trendy spots.