I think they should be compared to how well a literal rerelease of the original would do.

I think part of the evidence is just how absolutely long lived Frozen 1 has been. Nothing has been able to even come close to unseating that, not even its sequel (they were very smart to keep everything similar enough so that Frozen 2 merchandise can substitute for Frozen 1 in a kid’s eye).

It’s very indicative that people jump to movies that have been out for a decade or more, and probably can’t even name most of the more recent releases.