No, five years ago, it would have been too early to call it a disappointment. Now, it
is a disappointment, and there will not be 5-10 years for this to course correct, probably only 1-2 years -- if they play the Kubernetes card perfectly.
There is an extra dose of disappointment because on technical merits, GCP's basic VM substrate -- Compute Engine and Cloud Storage -- is far superior to AWS even five years ago, but AWS kept their ear to the street, anticipated every managed service and ancillary feature that their customers could have wanted, and executed relentlessly. Google has not mounted even half as vigorous and urgent a response as needed under the circumstances.
There is nothing at the outset that would prevent someone from choosing GCP, many might even be predisposed given the reputation of Google's own infrastructure, but when more and more of the tasks that you might want to offload to cloud are still not available or not reliably working on GCP, and you're stuck with operating VM's, you might seriously consider the competitor, and once that decision is made, you are not coming back.
It's an execution, and perhaps cultural, problem with Google, not one of technology or market.