After many years of working with AWS almost exclusively, I recently started a new $DAYJOB where our primary public cloud provider is Azure. A couple of days ago I was chatting with a co-worker about something, and he literally says "I think we should just chuck it in S3 and call it good" (paraphrased slightly, due to my imperfect memory).
It struck me as odd for a few seconds, and then I realized that exactly what you are talking about has taken place. S3 is so dominant that it's become the default label for object storage in the cloud.
Still... I think the bigger problem isn't whether or not Google plans topull the plug or not, but that it has a reputation of pulling plugs to such an extent that people factor that into a decision of using their services.
When it's something as big a choice as a cloud provider that can cast a long shadow over their offerings.
Try using apache-libcloud to make your deployment and programs cloud agnostic. Also try using smaller alternatives like hetzner or scaleway.
Once you go down this cloud rabbit hole you will be hold hostage to whims of these providers, where they can shutdown any service at their will or ask to pay an arm and leg. Also try to have non USA cloud providers as another backup option in the long run.
Developers these days say "Chuck it in S3" or "Run it on EC2". I feel they have a strong advantage because they've kind of come to own the language of the cloud.