We run a few Github bots & a function that updates a Route 53 record on serverless. (Security didn't want to give permission to R53; "too much, too broad"; a lambda that exposed only the necessary action to the service that required it was the compromise). But it's all extremely low-frequency stuff with no or little state, where the costs of a VM would far exceed the costs of "serverless". It was the right tool, for those jobs. (& it's usually niche stuff… I'm trying to think if I've ever worked somewhere with something core on Lambda or the like…)
But also got tons of VMs. Lots of VMs. Probably too many VMs.