FaaS is almost certainly a mistake. I get the appeal from an accountant's perspective, but from a debugging and development perspective it's really fucking awful compared to using a traditional VM. Getting at logs in something like azure functions is a great example of this.
I pushed really hard for FaaS until I had to support it. It's the worst kind of trap. I still get sweaty thinking about some of the issues we had with it.
Though I never really understood the appeal of FaaS over something like Google-Cloud-Run.
it SUCKS. There's no interactive debugging. Deploy for a minute or 5 depending on the changes, then trigger the lambda, wait another 5 minutes for all the logs to show up. Then proceed with printf/stack trace debugging.
For reasons that I forgot, locally running the lambda code on my dev box was not applicable. Locally deploying the cloud environment neither.
I wasn't around for the era but I imagine it's like working on an ancient mainframe with long compile times and a very slow printer.
This is the least of the problems I've experienced with Azure Functions. You'd have to try very hard to NOT end up with useful logs in Application Insights if you use any of the standard Functions project templates. I'm wondering how this went wrong for you?