generally speaking, isnt using vps a lot less expensive than a managed service like cloud run? im assuming the “websites” doesnt require to be always available 24/7 (hence the cold start is fine)?
Don't underestimate cold starts though. Will be a long time until you need to worry about that if you're backend is written in Go or Rust, but you can hit painful starts pretty quickly when it's Nodejs. Really comes down to (unsurprisingly) image size.
If coldstarts are a problem, things like fly.io are incredible. Just set the minimum amount of instances to 1, pay 5$ a month and you don't need to deal with anything.
It wasn't immediately obvious to me how fly and Cloudrun compare, but the way I think about it now after having used both:
In Cloudrun you don't think about any servers, you give them your image and they'll do the rest. It feels serverless in the sense that you don't think about machines.
Fly meanwhile is much closer to the infrastructure. It feels more like "we deploy a docker image to a VM for you", which let's you much more granuarly control what's going on beyond that.
Less magic, but in a good way because more predictable results. Cloudrun has a few fun corners (like no CPU between requests unless you explicitly enable it) that can lead to fun side effects and just make it harder to reason about.
If you're at the point where you're concerned about cold starts and using a service like fly.io why not just skip the (unbelievable, no-one-knows-this-stuff) complexity and use a $5/month VPS?
"Simply" using a 5$ VPS sounds great until you need to start writing systemd files, need to keep the box updated, want to deploy straight from GitHub,...
Nowadays all linux distros offer an unattended way to do packages security updates and reboot the node.
The 0.5G instance has a minimum cost of $10 a month, before any kind of traffic metering, or what have you.