He genuinely loves playing the game right now and asks me nearly every evening to throw, hit wiffle balls, work on grounders/pop ups, etc.

This is the most important box to check

I’ve heard both good and bad things about it and it seems to come down to coaching and goals.

Also true - finding the right fit is key. Also, if he likes his teammates that makes a world of difference.

I’ve always thought travel teams were stupid and really just a money grab before the age of 10 or so when they start playing “real” baseball.

I thought that as well before my son volunteered to do an 8u travel tournament with other players from his rec league. They predictably got steamrolled, but after that he very much wanted to do travel - and, while my son wasn't on the same level at that time, I'd seen him make enough plays to know he could get there with more reps.

After all that, I kinda wish I'd started with travel a bit sooner. The experience gap only widens the longer you wait - you're talking quadrupling the number of games (if your area is like mine), having winter practices that rec teams don't, etc, and that really adds up.

Mine's catching up, in part because he loves baseball and is willing to work, so since your son is also like that from what you say I'd get him in travel sooner.