That also excludes stateful apps like Elasticsearch that would not be able to run on Cloud Run. Not sure what Google product is appropriate there.
We migrated our stuff from DigitalOcean around 2018. At the time, we briefly toyed with the notion of self-hosting Kubernetes on DO, but it's complex to manage, and we don't have any dedicated ops staff. GKE is significantly easier to manage.
At that time we migrated, the things you mentioned weren't available/mature, I think. Even today, I'd choose Kubernetes over a complex mishmash of different systems. I like the unified, extensible ops model. In fact, I'd go so far as to say that I wish all of GCP could be managed as Kubernetes objects.
Sounds like you've identified an area of risk you should address
I had been using it since May 2018 but it didn't come out of early access till December.
For those that are not aware, App Engine Flex runs services based on Docker containers with autoscaling similarly to Kubernetes. It has way less features than GKE, but if you are just running a standard app that only needs to connect to a database that is more than enough.
Bonus points: you can have multiple services, like back-end and front-end and make them available in the same subdomain - to avoid CORS problems. You can also host your front-end for almost nothing with App Engine Standard. It has an awesome CDN built-in if you know how to use it.