Distance equipment, other events....entry and hotel all figure in to pro pool player$ thinking.
Since it's not the PGA, ones decisions are their own, somewhat.
How far would they travel for a race to 5, 7, 9 or 11 if it's 9 ball.
Would you drive further if it's on a 9 ft table than a bar table?
How far would I travel to a race to 7....8 ball event on tight pockets with good equipment, as opposed too.
9 ft tables races to 11, in a room with poor lighting, seating and air flow

.
When sponsors/commitments are not involved.
Rounders will always pick and choo$e their preferred eco$y$tem.