Hacker News Reader

I'm pretty sure GitHub actions do use a whole (though probably lightweight) VM. And I think AWS lamdas do as well, or at least used to.

Well, if lambdas are using VMs and have sub-second launch times, I don't think using a lot of github actions would cause much overhead.

This is a common misconception about Lambda and Functions. They don't always give you a fresh container/VM, but Actions does.