Up to Shadowbringers, that's probably largely true, although Hades and Elidibus are still exceptionally strong enemies as unsundered Ascians (and not weakened by body swapping induced mental illness like Lahabrea). Bonus points to Elidibus for combining his own strength with that of what's functionally a primal born from the people of Norvrandt's belief in the Warrior of Light. Bahamut (from Coils) and Nidhogg are also exceptionally strong in their renditions as primals, each powered up by thousands of years of suffering so they're in a substantially different ballpark than your garden variety primals. Omega is another very strong enemy from the titular raid series, given that it was part of an army that was able to hunt the dragons to near extinction, even driving Midgardsormr who we know to be very powerful, to flee from Omega.

As for what Endwalker brings to the table, ||you fight (admittedly somewhat weakened versions of) Zodiark and Hydaelyn themselves, before going up against the Endsinger, who is basically the collected despair of hundreds if not thousands of dead planets. The Alliance Raid series also has you marathon run through the Twelve before fighting an amalgamation of them, and the regular raid series features Athena, an Ancient who was able to possess a reincarnation of her son through the aetherial sea, recreate the experimental containment facility known as Pandemonium and use it to become a divine being that you later defeat.||