I was in a startup with a small team and we used Kubernetes for servers that required more than 8 GB memory. Cloud Run and App Engine doesn't offer more than that, at least not at the time. The alternative were to deal with virtual machines ourself with Ansible scripts, and I'm not sure how that would auto scale + it would break the existing flow of Docker containers for everything. It took a while to figure out how to put Kubernetes in a closed VPC, but after that it was fairly straight forward.