You are correct in general. I'll just add the nuance that when an open-source project gets beyond a certain popularity and usage threshold I'd expect the project's governance to take a stance that's more responsive to PRs.

That doesn't include any money incentives and that is likely the problem here.

Maybe `actix-web`'s author should apply for GitHub sponsorship. Maybe small sums of money every month will motivate him to take PRs more seriously.