How did "old elite" universities/colleges lose their prestige? (Letran, San Beda, Sta. Catalina, St. Paul)?

Lagi ko na lang naririnig sa boomer parents ko and my grandparents about how good some schools were during their time and how ito yung mga schools that the rich and educated wanted their children to go to. Among them: Colegio de San Juan de Letran, San Beda College (kasi hindi ba University nung time nila haha), Santa Catalina College, St. Paul University, etc.

Parang UST na lang ata yung natira among the "old elite" schools that still has prestige. Ateneo and De La Salle were still not considered prestigious academic institutions until around the 1980s pa. Letran back in the day was competing head-to-head in terms of prestige with UST.

Been trying to look for info online kaso puro about history lang ng mga schools na yan eh. Yung ib got destroyed during World War 2. The formation of the UAAP and sports popularity probably has some part in it pero I'm sure that's only a small part of it considering the long history of such schools.

Anyone care to share their insights or info as to why?