I think we somewhat agree.. Uncompensated on-call is not acceptable. Even if you're not busy, there is an ever-present burden to knowing you could be interrupted at any moment that takes a toll on your personal time.

But as long as the expected cost of downtime outweighs the financial cost of keeping someone available to fix it, on-call in some form will be inevitable. (There are a lot of instances where the cost doesn't make sense, and we should just accept the system being broken until 9am)

I don't think on-call needs to suck though. IMO "staffing issues" (whether it's headcount, time, competing priorities, etc) are resourcing issues and I believe better tooling can absolutely help with that - either by reducing the resources required to fix it or by making the cost of the issues quantifiable. Thanks for the good luck :)