I would be completely fine with 2D.
The move to 3D was decent, I personally enjoyed Y and specially Alpha Sapphire, it was nice playing an old gen in 3D.
Now Pikachu/Eevee... damn, you can't even battle wild pokemon!
After Pokemon Go the series is going completely downhill.
Sun and Moon weren't directly affected by it but were already pretty lame, and the Ultras basically the same.
Even the anime was greatly changed.
Now Sword/Shield with stuff like Dynamax and not letting you transfer all your pokebank stuff into it...
I'm playing Soul Silver right now and wondering how did such a great series has gone so wrong.
But hey, the money never stops coming, so how to expect anything to ever change back? The money says it's working this way.