Wired2fish had an interesting article comparing the three. I generally wouldn’t direct anyone away from IDO, but I think this is well worth the read.
I got out of tournament fishing around 2008ish and considerable changes have taken place since. Now there are more “pro” anglers than ever before. Early days were sub-tours that made for a competitive means to move up to an elite level. Now, I’m my opinion it’s a cluster. First and foremost, do you have the money to tour….next is where your most competitive. As guys moved into MLF, it left the competitive side of things open in the other tours.
A few of the state reps from state level organizations are on here and can better explain the association with local clubs and the pathway to gain entry.
https://www.wired2fish.com/opinions/comparing-pro-bass-fishing-tours/