Emet-Selch, Varis, Nidhogg, and Nael (technically primal Bahamut) all work excellently as villains for different reasons. Endwalker failed in that aspect because they fell flat on their face trying to be "Shadowbringers 2: Electric Boogaloo".

The other games in the series have their own share of well written antagonists though. Kuja, Kefka, Jenova (no, not Sephiroth himself), Vayne are all just as good.

And I disagree on the take about the genre. As always it just comes across to me as the typical FF fan that doesn't bother stepping out of their SE bubble to notice all the things other jrpgs do better these days even though their visual style clings to mediocrity by comparison. But then again visual eye candy is modern FF's bread and butter.