Too much has been made of that term katèchon. All it means is that it was a final barrier or impediment preventing the floodgates from opening. Period. It does not mean that either Ratzinger was some great defender of the faith (akin to St. Pius X), as the Bennyvacantists would have it, nor that Trump is the reincarnation of a sainted Catholic King.
It's more of an apocalyptic notion that there's a last barrier or impediment (even a passive one) holding back the deluge, where the floodgates opened with Bergoglio and Biden respectively, where after those two the evil was taken "to a new level".