My son did not like his first year of summer ball. Was in a basement with 5 other players, and had a coach that was basically trying to do what the OP described, get a name for himself to get a better college coaching job. As a pitcher, it didn't make a lot of sense for him to be there. But he did seem to enjoy participating in the community volunteer activities, and the camaraderie. But he really wanted to be home training. As a pitcher, I had to agree with him.
If we go back to the 40 vs. 4 year plan, summer ball doesn't help the 40 year plan at least for the majority of pitchers IMO.
Flip side of this. I mentioned in another thread that a kid on my son (2022) incoming class de-committed and signed a pro contract. He was able to do that because he played summer ball and was seen by scouts.