The terms "incubating" and "graduation" have meaning to others, even if you choose to ignore them:
https://www.cncf.io/projects/
CNCF projects have a maturity level of sandbox, incubating, or graduated, which corresponds to the Innovators, Early Adopters, and Early Majority tiers of the Crossing the Chasm diagram. The maturity level is a signal by CNCF as to what sorts of enterprises should be adopting different projects.
> Are there any foundations that don't operate like this?
Presumably. My main experiences are with the Apache Software Foundation, though, which in terms of "incubation" operates similarly to CNCF.
> Are foundations good at all for anything?
The answer is foundation-specific. But in general, foundations allow for pooling of resources and wisdom such as legal services, and allow for consumers to know a lot about a project's governance and status at a glance in a way which is difficult to ascertain for a standalone project on the web or Github or wherever.