How can you be so certain? The project is barely 6 years old and so many APIs are JUST reaching v1. And companies are still using mostly barebones K8s, we are yet to see how RedHat, Azure differentiate on top of it and we get to see all the "distros"

By the market position of Amazon and Microsoft versus what Google keeps trying to do, and there are enough candidates for that 3rd place.

Cloud is still very much a blue ocean domain. Azure's rise has been driven by bringing in companies from the huge on-prem market into Cloud, not by attracting users away from AWS. We are nowhere near maturity level to even consider that current market leaders will stay in place for next 5 years.

Hope is good I guess, maybe by then Google has managed to finally provide enterprise level confidence on their offerings.