Anecdotal single point of evidence: I was trying something for a project at work, and between raw OpenGL, unity, and unreal, the latter two let me get a POC up and running way faster. I work with dozens of ex game industry people, and none of them have done anything from scratch for AAA. Every major studio has tons and tons of layers of engine abstractions to make development easier and faster.

An apt analogy in the service world is that when I want to write a service, regardless of how many years experience I have, I don't implement my own load balancer. Could I? Yes. Should I? Only if my project is a load balancer.

Build what you need. Buy/ participate in OSS for the rest.