If you're putting your service behind CloudFront, you're probably aiming for DDOS protection and low latency or something that you can't easily get from a VPS.

If you're putting your service behind CloudFront, you're probably aiming for DDOS protection and low latency or something that you can't easily get from a VPS. Of course, you can put your VPS behind CloudFront, but you would run into the same issue (albeit the fixed capacity of your server would effectively cap your bill). A single VPS is great if you don't need reliability or scale, but if you care about those things you probably need at least a few of them running behind load balancers, and you probably don't want humans manually poking at them (but rather you want some reproducibility). Moreover, there's a bunch of host management stuff you're taking upon yourself--configuring metrics collection and log collection and SSH and certs and stateful backups/replication/failover and application deployment and process management and a whole bunch of other things that come for free with serverless. Implying that serverless/Kubernetes/whatever is just hype ("cool kids") while ignoring the pretty significant discrepancies in requirements is pretty silly.