Do you think you need to own the cloud to compete in cloud gaming? Or could someone "rent" the cloud and compete?

It seems like press that covers this topic take it as a foregone conclusion that Microsoft and either Google or Amazon will win in the space because of their cloud infrastructure.

I get that Google Stadia has stumbled so far and Amazon Luna doesn't seem like a home run either, but really no one is dominating the space yet because it's so new and US broadband deployment so poor.

Could a client of Microsoft or Google or Amazon leveraging their cloud infrastructures compete with the owners? Or is owning the cloud an absolute requirement to compete?

Nah not necessarily, partnerships could work. Ubitus, for example, is already saying many more big 3rd party games will be coming to Switch via their servers. Even without having servers as their own, a 3rd party company bringing them over is just as effective. They only get a cut of the profits, but Nintendo does not need to worry about any headaches on the server end of things. Plus these cloud versions are essentially PC ports with controller inputs, making it worthwhile for 3rd parties to bring the games over as even minimal sales will equal profit.

The real question is not so much who owns the servers, but more who has the most accepted business model for the games.

What do you think every single server of every gaming company runs on?

PSNow is running on Microsoft servers.

PS Now runs on Azure, and therefore I don’t see it as a competitor in cloud gaming. I fully admit they are a juggernaut in console gaming, but any gains they make in cloud gaming MS wins too.

So to answer your question, I think only Google, Amazon and Microsoft are the only competitors because they OWN their server farms. Any competitor renting those servers is essentially a puppet of the Cloud big 3.