NCAA keeps a bunch of it to run all the championships in each division and pay their staff and stuff. But each game played in the NCAA tournament by a team is worth a tournament unit credit, and that pays out around $2 million to their conferences (who split it among their members, sometimes evenly sometimes more to the team that earned it).
it a tad more complicated than that
The participants are paid from a annual pool of $270,000,000 free each appearance in every round is worth 2 million technically to the conference not the team
That tourney grosses $1.2 billion
My personal opinion is the pot could be doubled but that’s me
Remember men’s basketball finance NCAA administration costs, which are excellent, plus annual convention
also most Championships at every level , plus a distribution for scholarships money to members
There are 1100 member schools in the NCAA
You
you can increase major conference revenue without breaking away
Or even expanding the tournament
Reduce the participation of conferences from 32 to 20 or even 16
You automatically make $24,000,0000. To $32,000,000 available
People wouldn’t notice the difference
You could even keep 32 , D1 conferences with a relegation
A P4 tournament is a stupid idea even for them