This is a very good point. Even if you don't want to self-host and you'd rather use a service, having the software available as open source so you can self-hos

This is a very good point. Even if you don't want to self-host and you'd rather use a service, having the software available as open source so you can self-host if you so choose, makes it more rational to use the service, because it makes it harder for you to be screwed the way OP's startup was.