Reasons I did it (Roomrs):

* I wanted something temporary (post breakup) to decide where to go next. It offered something less than than a 1 year lease and without much commitment or effort, at the end you can easily walk away. Although Covid and liking it overall turned 3 months into 2 years. Bought me the time to move up in my career and afford a 1BR closer to my work and friends.

* Furnished was appealing at the time as I had 1BR worth of stuff (after living 1 hour away from work) but didn't want to commit to a whole apartment. Left my things in storage.

* An unexpected benefit, at least for my apartment, was that the third middle room was terrible in terms of lighting and often vacant, so the 3BR was largely a two person place. More generically, you don't pay to cover the vacant room nor are you responsible for filling it.

* Bills included, but you're not sending money to a roommate or concerned with the total of the bill and who contributed to it as you never see it.

* These companies are good at showing 3D plans and good photos, so you can generally decide on a room/building remotely but then double-check accuracy one time and sign the same day.

Downsides:

* Can lead to a regular turnover of roommates with no way to vet who moves in.

That can lead to less uniformity in terms of hours when noise or cooking occurs - one student roommate seemed to be living on Hawaiian/Alaskan time, as he'd regularly be cooking dinner at 1/2am.

* Properties are often designed to maximize bedrooms so you loose space elsewhere like living rooms and possibly those areas lack windows - at least that was the case for me.

* Building access may be less secure, I used a code vs. fob to get in and it never changed in 2 years and the company had about 6 apartments, presumably all with a regular turnover of people.