I had roommates and a rent-controlled apartment in my twenties and thirties. I was there so long that when roomies turned over, I increased their share of the rent. I went from 50-50 to 30-70 over time. Saved like hell and bought my first house. It was too far out for my job so I rented it out and kept the apartment and the roomies.
When I was 38, I bought a 2+1 condo and lived alone for the first time in my life. It was hella expensive and I didn't like being so house poor. Then a friend needed out of a bad situation, so I ended up with a roomie again.
When the job dictated a bigger home (I needed a garage for sample storage.), I bought a 4+2.5 townhouse and got another roomie. He stayed for five years. When he left, I decided to go it alone. I could afford it by then, but I still missed the money coming in.
I didn't get married until very late in life, so my situation is not quite typical. However, I know there are lots of single ladies out there who could easily adapt to this lifestyle. I traveled for work, so I loved that there was someone at home. Some roomies became lifelong friends, others were passing ships. By interviewing them as if they were job candidates, I managed to avoid duds. In fact, the only clinker was someone I worked with and thought I knew reasonably well. Fortunately, she gave notice on the day I was going to give her the boot, so even that one worked out in the end.
In the end, all of this allowed me to FIRE. At 55, it wasn't terribly early, but I was never a huge wage earner and I've lived in L.A. and the Bay Area all my life, so housing is crazy expensive. I also made sure to live for the moment, including travel to see friends and relatives and the wider world. As a cancer survivor, I was always mindful of the possibility of recurrance, so I probably saved more than I needed to, but I was careful to balance living for today with saving for the future.
Had MMM, ERE and the like existed sooner, I'm sure I could have done it earlier. As it is, I can't think of anyone I worked with who retired at a younger age.
Yeah, roommates were absolutely worth it. If I lived in a part of the country where multi-unit housing was plentiful, I'd do that in a heartbeat and have roommates.