This is kind of a straw man don’t you think? Really small startups sure but I’m sure many places that self host have an ops team that can and does respond to outages on their systems.

Your example also suggests another factor: downtime overnight might be less consequential than shorter outages that occur during working hours.

Have you ever troubleshot an outage with a whole team? I am strongly in the belief that any more than two people working on an outage makes it last longer.

Properly run incident management can have three dozen people involved with no negative impact. You need the incident manager to coordinate, communicate, run interference. You need a clear set of rules for who will have what role and responsibility. Combination of voice and text, multiple chat channels.

But yeah, if you have no plan or organization, too many cooks is detrimental.