Also, the founders of Elo were creatives, not programmers. So they couldn't throw a microSaaS on a VM, forget it and go write the next microSaaS, rinse and repeat.
I think, though, the people who can and do bootstrap small businesses like that don’t necessarily hang out here. The site is literally VC-owned, after all.
There are tons of them out there.
You can do a lot with a small VPS and a fixed amount of bandwidth.
Find something that 100 people will use for 5 bucks a month. IF your bills are paid and you have a day job, that's some nice pocket money.