Google pays their oncall a % of their full-time base salary depending on the oncall tier (5 min response time vs 30 minutes).

This should probably be required - there is a different mindset and set of restrictions when you're expected to pick up a page. It also forces companies to use on-call judiciously - not every service needs a 5 min SLO.

When I worked there I spent a lot of time talking teams out of a 5min commitment. It’s really crazy.