Crossplane could be one package that customers would not want to use directly from a major cloud provider. You'd never trust AWS/Google/etc to really give equal footing to a competitor. Separately, I'd prefer to trust the company behind the open source software as opposed to some other upstart. So this model may really work.

One observation: Crossplane and Upbound seem a little too unrelated of names. Github has benefitted from being almost synonymous with git (admittedly, Github also created the opening for Gitlab at the same time).