Is Psycho the greatest career comeback in recent history?

Yes, also the song was a top 3 kpop song for a majority of kpop fans in 2019

Yes. And Queendom continued this success (well not Psycho successful but still successful) for Red Velvet.

I suppose so, but the song itself is mid-tier at best. Zimzalabim and Umpah Umpah deserved better

yes!!!!

Perhaps.