Their costs were super reasonable as an ongoing concern too compared with my experience at various startups. Losses that small are practically pocket change. If they weren't able to win investors over with their service's relatively strong performance since launch, what hope do these other services have when the investor money dries up? Do they have secret sauce that isn't "sell customer data to OpenAI" and "run more ads"? The former works right now but its days seem numbered as a realistic revenue source, and advertising becomes a worse revenue source with every passing day.
i.e. from the sources I've seen, Bluesky is operating on something like $20m in total investment. That's a good amount of money, but what happens when it dries up? What's their revenue plan? Whatever it is, I hope it's more compelling than Twitter's answer for keeping the lights on, more successful than Cohost's model, and more substantial than the Fediverse's.
From what I can tell the nail in the coffin to Cohost was having their big revenue feature unceremoniously killed by Stripe, which is sobering. Always sucks to have to put your fate in the hands of payment processors, since they have a long track record of being capricious.