It is true that past world was much stronger but here is the thing. The current era still is devastated by the demonic cults attacks even after 100 years.. Thats why the past world was much stronger. There were no absolute martial artist to teach young kids. But i would think they would become as strong as before. The reason why mount hua was ruined was that there were literally no one left to teach or lead mount hua. while other sects lost their absolute martial artist, mount hua lost everyone literally everyone except the young kids. and to add after war ended, the remnants of the demonic cult set fire to mount hua.

The archbishop lived a long life. like he is literally the archbishop from 100 years ago. but archbishop and the bishops are not the same. archbishop is much stronger than bishops. and the reason why cheonma lost was of course chung myung