If you have a goal to play professionally and are invited to such events as:
PG National
PBR Super 60
PBR ProCase events
Then of course you go. This is where you develop a following amongst pro scouts.
Of course you attend the PBR events after you sign your NLI. The PG National occurs the summer before the NLI so this is the primary launching point for the draft (before other events like East Coast Pro, etc.)
If getting invited to the PG National or Super 60 is a goal, you may feel the need to attend "lesser" events which are billed as "stepping-stone" or "feeder" events. Of course you must think carefully about these and attend only if you really feel you have metrics similar to attendees of past big events and need to show them.
It is certainly an individual choice and there is no "correct" answer.
But if your son aspires to play professionally one day then why wouldn't you try to get invited to one of these coveted events?
Clearly many people do!
Another thought: take a look at some of the recent schools that have announced they are discontinuing baseball. The 2021's committed to those schools have now announced they are back in the recruiting game. Gee, I hope they had something (measurable) to show potential suitors. So if a kid feels he has worked hard and KNOWS he has the ability to show improved metrics, it is certainly worth giving another showcase some consideration. You never know what's going to happen.