In Japan you have lots of smaller federations.
It's not about being bigger or better, it's about supporting combat athletes at the earlier stages of their career.
When you have no record, bigger promotions won't take you on.
So by having some amateur tournaments and then your first pro matches in these promotions, you can build up your record and get noticed by these bigger organizations.
They often visit these smaller promotions to scout for talent as well.
In the west UFC has come up with lots of different formats to give young guys this chance, and you see more and more promotions popping up.