The Lore Powercreep Does not Matter
Yes, Riot has producing powerful characters since the removal of the Institute of War. No, this does not mean a damn thing for the lore.
Powercreep is a factor in game design because every champion should be able to contend with every other champion. Talon may have to lane against Aurelion Sol, but he can still assassinate the space dragon easily.
In the lore however, there is almost no reason for Talon and Aurelion to ever have to interact. Riot’s narrative philosophy is creating a larger world filled with smaller stories. Ornn and Volibear will continue to clash like the demigods they are, and Ekko will continue to beat up thugs in Zaun.
This is why I don’t think Powercreep in the lore is a big deal at all.