It can be really tough to get people out of the beige box mentality if they have never encountered anything different. The first time you blow away their production server(s) and replace them with what is checked into git can be rough.
Then you get into serverless and suddenly they can’t log into production anymore, and they have to instrument their code, and work within finite resources - all that stuff they ignored in college about manipulating datasets larger then core memory are suddenly relevant.
When we did our transition to serverless we found that the people who complained the loudest about their traditional servers being mysteriously corrupted were actually the same that had obtained admin rights “so they could work faster” and were going into the servers and blowing away configuration files, altering permissions, and making other changes. Once there was no more ssh and no more root privileges our outages dropped two thirds. Today it’s mostly third party outages impacting us and people deploying untested code to production.