This is apparently an unpopular view, but after thinking a bit about it, I agree with your premise. Splitting older millenials with gen X, and younger millenia

This is apparently an unpopular view, but after thinking a bit about it, I agree with your premise. Splitting older millenials with gen X, and younger millenials with gen Z makes sense, because instead of an arbitrary characteristics like "being 20 in the new century", this splits seem to better match some cultural changes that are not perfectly aligned with round dates.