This chart is saying the B12 is better than the ACC. I don't believe that. I don't think anyone does. If that's subjective fine, but they aren't better. I think round robin conferences have a huge edge on those RPI numbers, and that favors the B12 and BE. By the same token I don't think the Big East has been better than the B10. As for the SEC they were UK and nothing but Florida now and then for a long time. My feeling there is that those 3-4 numbers at the end are closer to what we can expect from them.
But the past isn't important. From 2020 forward I think the ACC is still at the top, the B12, B1G, Big East and SEC will bounce back and forth year to year in the 2-3-4-5 slots. The Pac could make a comeback, but the trend is the reverse of the SEC. I think it's pretty competitive among those four conferences with UConn joining the Big East.
As for data, you left out final four appearances. ACC: 5, B10: 5, SEC: 5, B12: 3, BE: 2, PAC: 1. It's anecdotal but if you go back one more season, schools currently in the Big East are still at 2, and schools currently in the American are at 2.