Unless you use BW every minute of every day, including when you sleep, then you’re in no position to counter self-hosting with your anecdote.
But I'll add another anecdote. I have had the same experience. I have never noticed any downtime from bitwarden but my 3 node kubernetes cluster that would host vaultwarden has gone down multiple times. Sometimes just for maintenance.
I self host a lot of stuff but my password vault is not one of them yet.