Most viewers have switched to MPBL and they also find it more entertaining especially if there are celebrity players who are showcasing their skills on the basketball ring. Manny Pacquiao always try his luck in all fields that he wants and he never stops until he succeeds which is really impressive.
I don't believe in that, you should show some proof to convince me.
PBA is still more popular than MPBL and I don't see MPBL is competing with PBA since the players of the PBA are way better than the MPBL players, and some PBA players are representing our countries in international competition.
Here's an article to describe the competition between PBA and MPBL.
PBA and MPBL Discuss Ways to CO-EXIST Without Unintended COMPETITION
They can co-exist without competing actually as MPBL is just new while PBA has been here for many decades, meaning the fan-based for PBA is bigger compared to MPBL, plus PBA has more media exposures as they are broadcast in one of the biggest networks in the country which is owned by one of the PBA owners.