Yeah, no. They need to 'follow the sun' and have people who can handle things in each time zone around the world instead of waking people up in the middle of the night.

Track how much sleep you're losing and document how unsustainable this is to HR as you leave. Uncompensated, sleep-depriving on-call is not the norm nor should it be for a company of any decent size.

May be worth at least looking into contractors in another time zone to cover your overnight on-call. My team did this a couple years ago and it's significantly eased up our on-call rotation, at least to the point that we're only getting called for major outages while the offshore team handles the minor issues, change/release support and things that go bump in the night. There's still weeks where we put in significant time if there's a major issue, but we're not getting woken up for every little alert that goes off.

I should also add my team has an automatic comp day at the end of our rotation, though that's handled on a team-by-team basis. Plus it's not uncommon to get an extra comp day if you have a particularly brutal week or support some major off-hours work.