Things improved a little bit after some time, but the idea of on-call developers is still very much ingrained in the incident management process.
Now, personally, I don't quite understand why a developer would need to be woken up at midnight to diagnose something that cannot be patched by him or her alone.
Perhaps the issue is that our process is dysfunctional, but I'm wondering if it is necessary, or just common across the industry.
My partner is an executive chef at a private school. It's one of our country's top schools that gets the occasional visit from people with royal titles (and one might soon be King), so think super rich kids: there is a lot of pampering. All of a sudden through this Covid thing we're all working through, there are texts and phone calls at 5:AM "There's a kid with a new allergy coming in today. Make changes in the lunch menu to accommodate them." This is literally a situation where one could ask, "Shouldn't this be an email, CC'd to others involved, too? And maybe even the day before so appropriate food items can be ordered?"
It's super annoying and clearly goes against how things are normally done in a well managed business. A lot of companies are clearly taking advantage of all the workarounds this pandemic has forced us to contend with. Except usually the abuse isn't even related to pandemic conditions.
A lot of people are technically working 24x7 nowadays.
We had an informal rotation in the dev team so there was always a named person who'd make sure any customer issue got an intelligent first response - up until a certain point in the evening. That was to ensure we were able to ask for data we needed from customers in other time zones, then look properly when the team were in the next day.
I have known people on 24-hour call in companies that had infrastructure that was critical to their business (i.e. "as a service" sort of deals).
(personally, where I see developers are already doing some out-of-hours support work voluntarily, I think overformalising would put people off and be counterproductive)