If you're using the App Engine Flexible editions, it's really easy to not worry about vendor lock in or really even deprecation much at all. E.g. it's easy to run a basic Node, Python or Java backend in App Engine Flexible, making use of a MySQL or Postgres DB in Cloud SQL, so you don't have to worry about managing servers at all and you get all the benefit of automatic scaling without the semi-nightmare of running your own kubernetes cluster. Then even if App Engine totally went away you just have a normal Node, Python or Java app running against a MySQL or Postgres DB that is pretty trivial to migrate to another platform.