How to enable Gatsby Incremental Build 2023?

In the short term? Unfortunately, not. In the long term, yes, there would be attempts made in that direction, but there are platform limitations that simply can’t be raised without dropping the entire thing and moving to a different solution.

Gatsby Cloud was handling only Gatsby deploys. Netlify is framework-agonistic. Thus, the approach these two systems used to handle site builds is totally different. The underlying primitives and infrastructure is different. If you’re expecting this to change before Gatsby Cloud is gone, sorry to say that’s not going to happen.