Yeah, in terms of numbers, the Arian crisis was as extensive. What makes this different is precisely, as you say, that the Pope didn't go Arian (although he was arguably somewhat week and may have compromised, likely under duress).
Yes, Pope Liberius, for example, was weak, but then one theory is that the Arians kidnapped him, and threatened his life, so he caved and condemned St. Athanasius. It's difficult for me to fathom how so many Catholics back then could fall for the lie of Arius, in that he believed that Christ did not share the same divine nature as God the Father. Like the Modernists of today, it seems that Arius was only doing what he believed to be right. He didn't seem to trust that the Church always had the Truth, and that Truth doesn't change.
At least back then, Catholics were forced to focus on the specific heresy of Arianism. They didn't get sidetracked by the ideas of sedevacantism. And back then, the violence of the Arians was a good reminder too that what they were dealing with was serious. But Our Lord eventually righted his Church. Thanks to many saints who relied on Our lord, and were willing to work to that effect. And thanks too for a council (Nicaea) that condemned Arius and Arianism.