Before at least Gen 6, every Pokémon game had a teeny tiny regional dex, and most of the early route Pokémon would just repeat for most of the game. This is especially bad in Johto. XY, SM, and especially SwSh and SV improved on this tremendously, meaning that they are the objectively most replayable, content-packed mainline stories in the entire franchise. Additionally, the Battle Frontier is just mimicked from XY onward with facilities of different names. Nothing was taken away except the shitmons that were excluded from "Dexit" (and mostly temporarily), but this is a moot point because most Pokémon needed to be traded or transferred into the "Golden Era" titles, meaning that the "DS Golden Era" titles had their own, more severe "Dexit".

The Gen 4 games lack in quality of life when compared to SwSh and SV, because you can make any Pokémon full IVs, EVs, and perfectly natured with a perfect moveset in SV without nearly as much hassle.

The DS games are also either very easy, or have difficulty problems like Johto's level curve. The Pokémon equivalent of the "scienfitic community" in expert Nuzlockers, let's players, and video essay creators analyzed this to the death and reached consensus that Johto is the worst region.

Even when pandered to; and given BDSP, which improved upon D/P/Pl, the "DS Golden Era" crowd keeps complaining.

Graphics have never been better in the Pokémon games on the Switch, but Golden Era lobbyists cannot help but keep on their nostalgia goggles.