One thing I haven't seen mentioned in the comments is how easy it is to quickly iterate on Cloud Run. I built a web app that uses Cloud Run for 90% of my server needs (Cloud Functions for the rest). One of my favorite features is that I can make some local changes, upload the container, and click a button to deploy the latest version or A/B test. Then if I notice anything weird I can just as easily revert the changes, which has saved me a few times. Admittedly, I haven't used VMs in years and it might be just as easy there these days with containerized VMs, but I don't know. Cloud Run was so trivial to set up that I didn't want to waste time on alternatives. Another really nice thing is that it integrates nicely with Firebase, which I use for hosting.

As my site matures, I might move some predictable parts to containerized VMs to save on costs. I have a crawler-type service that has extremely consistent traffic that probably shouldn't be on Cloud Run, but I did it anyway due to being able to iterate so quickly (see revisions here: https://imgur.com/fkFtIRM). Cloud Run also has a free tier which was enough when I was starting out and prototyping. It's also nice since my site gets very little traffic at night so at the moment the cost is not too bad. This is what my billing looks like: https://imgur.com/gIo3IGJ

If I was a big company or my site got super popular I might do things differently. But for a side project it has made me enjoy programming more than anything I've used before because I can focus 95% on code.