I find the argument that you shouldn’t be using serverless because you don’t have money to throw on devops a bit… strange? Isn’t the big reason on using serverless to avoid spending money and time to managing your own server?
And IMO the lambdas-are-cheap argument is more like that lambdas are expensive, but they multiply to your scale, so it’s super-cheap in small startups. I view lambdas as a starting point for PoCs — they eventually have to move to VPCs, but lambdas are free if it gets no traffic.
And that’s why I’ve mentioned lockin-free APIs: lambdas are terrible if you can’t migrate away from it. But if you can without much effort, it provides pretty good value.