Just to add... heard directly from a HC at a P5 this summer say similarly he does not reach out to the travel coach too often, saying he almost always only hears the good things. Will connect more reliably with the HS HC... not on talent/ability though, just to get a better sense of how the player is in the dugout, off the field, and in the classroom. Not to say that this HC doesn't use the travel coach for connecting with a prospect, especially before his junior year.
As for the original topic, I've enjoyed just about every camp my son has attended, and I say that knowing he has not yet received a single offer to date (FWIW, he's a 2020 LHP 6'2" 165 cruising 81-83 w/ 1300 SAT as a soph). Just made a decision to spend the time and money without the expectation, and the ride thus far has been fun. Son and I have learned a lot - not so much from any baseball instruction at the camps - but it's hard to learn about all these schools without first stepping on campus and listening to their coaches directly. My son is a bit of an introvert, and I think it helps him open up a bit getting to know these coaches as people first, not just names, photos and bios. And he's definitely been able to form first-hand opinions about many college staffs from what he's seen and heard...no chance he's able to do that without all that camp attendance.
Knowledge is power. Yes, it can be an expensive hobby going this route, no surprise to anyone here, I am sure.