I don't have any problem with "serverless". Years ago I wrote a nginx handler that routed to .py files and ran them inside an lxc container, while at a hosting company. Fronted via haproxy, and documented with sphinx automatically.
My problem is the hidden costs. Sure lambda requests are low cost. But what about API gateway, dynamo/rds access. Then I'm writing a basic crud app. Low-performance low request rate, noncritical. There is this additional complexity, that just isn't necessary. Every day at my job I'm thinking to myself it doesn't need to be this difficult.
My usual route is django, django admin, and django rest. With an haproxy in front for load balancing. Dead simple and easy to work with. It's passe sure, but KISS. The alternative here is an api and a frontend. Several more projects to maintain. Tuning the projects to meet lambda size requirements/standards. The return on investment is minimal to me. If you can't automate managing a fleet of containers or vps instances then why're you here?
The vendor lock-in, is insane to me. You're pretty much at the beck and whim of the provider. They raise the prices, what're you going to do. You either go with the price increase or do a rewrite.
As I was sitting in these architecture meetings on moving too lambda. I was hearing several new packages/repos. New CI/CD, and configuration to maintain. During the meeting I scratched out a POC using EC2, Load Balancer, RDS and django to do what they were saying with half the code. But nope gotta be lambda.