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.
You might not be at the scale where this is feasible yet since that's probably multiple full-time engineers, but eventually the cost functions intersect.
I'm the CTO at a very small company. All our stuff is running on GKE. Our monthly bill tends is a lot less than $10,000/mo. We're currently in the process of splitting our stack into separate projects and clusters, because co-locating projects in a single cluster has gotten messy. We'll probably end up with 4-5. That will increase our bill by $292/mo, worst case, assuming the first cluster is free. For a company our size, it's not a huge expense. But these things add up.
Since moving from DigitalOcean, our Google Cloud setup has more than doubled our monthly bill. We're paying for more compute, but certainly not twice the amount, as we've only gone from 14-15 nodes to around 20; it's just more expensive across the board, both node cost and ingress/egress. We're even cost-cutting by using self-hosted services instead of Google's; for example, we use Postgres instead of Cloud SQL. I ran the numbers earlier today; the equivalent on Cloud SQL would be 3.4 times more expensive.
In short, Google Cloud is expensive, and it's not like the bill is getting smaller over time.
Developments like these factor in my choice of cloud provider for future projects.