Yet ... if R&R is true, there might as well be "no Church left on earth". If the "Church" serves mostly to lead people to hell, then we'd be better off without one.
You could argue that that Arian heresy is an example of a prolonged R&R situation (let's not get into the weeds on the "kind" of R&R, just a general point). You had a weak, ineffective, heretical-condoning pope, you had (according to historical accounts) 98-99% of the catholic clerics/population infected with the Arian heresy, you had self-espoused "arian-catholic priests" arguing with "I-agree-with-Arianism-but-not-your-kind" priests, and then you had "St Athanasius against the world", the only (maybe a handful of others) cleric who was truly orthodox.
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After Arianism went away (remember, Arianism had already been condemned multiple times before the time of St Athanasius, just like the tenets of Modernism have been condemned previously), there was not a re-consecration of bishops, nor a re-election of Cardinals, nor a re-election of popes, nor a re-installation of bishops into dioceses...the heresy went away and orthodoxy return when a 100% orthodox pope was elected (who also censured Pope Honorius). You can easily argue that 98% of the clergy at the time (including the pope) led people into error because as it was said "the entire world groaned under the error of Arianism." Very similar circuмstances to V2 and indefectibility didn't apply.