what would you say is the main difference between a beat that can have a life on its one, like say.. a knxwledge beat for instance (not the remixes) and a beat that a rapper is gonna lay a verse on?

do yall leave space for the artist on purpose?

You almost answered the question yourself with that last line.

I feel like beats that are songs or vibes on their own, have a lot more instrumentation and sound effects going on during the verse

While “open beats” leave a little more room for the artist to breathe which is very important in picking beats as a rapper. You don’t want your vocals clashing with some loud ass sample that a producer wanted to use as the lead vocal. It sounds sloppy. I prefer open beats only because I like write raps lol