I want evidence that the over simplification of job design has had any positive impact at all on the game's popularity and population. Because the game's growth is far more attributed to its marketing budget and MSQ. I have never seen a single person talking about FFXIV and go, "You should play it! It's such a good game because it's so incredibly simple and far less dynamic than in the past, which was what kept me away from it in the first place."
All I ever see is people talking about when praising the game is its story and nothing else. Is there any decisive evidence that the game would be less popular if everything about Shadowbringers and Endwalker was the same except that the game had maintain the same general level of job complexity from Stormblood or even Heavensward? Prove to me that keeping the job design depth that "old" players miss would be detrimental to the game's ongoing success. Because unless you can show me decisive evidence that the over simplification is what generated more new players for each expansion, then I cannot be convinced that Endwalker wouldn't have been more at least a tiny bit more successful retaining more "old" players who have gradually abandoned the game because of its simplification by maintaining the general levels of complexity from before while still pulling in every single person who has joined since then with its praise-worthy story and increased marketing budget.