If we're talking about GameFreak in the Switch-era, then no problem with the statement. However, they were some of the rarest devs to actually push their hardwares to the limit.
The 3DS games were incredibly demanding, while the DS used 3D assests as well and continued to evolve the 2D pixel sprites to almost perfection at the end of the 5th Gen.
I'd actually say the Switch is the first console where GF hasn't been able to efficiently push the hardware to it's limit as they could.
Strongly disagree. The 3DS Pokemon games did not begin to compare to games that actually pushed the hardware like Resident Evil Revelations, Kid Icarus Uprising, any Monster Hunter, ect. The fact that there were performance problems with the 3D in X/Y and the 3D was abandoned in later games on the platform has more to do with poor programming and optimization on Gamefreak's part than the games being technically demanding in the assets and effects they pushed. Pokemon games have never been among the better-looking games on their respective hardware. Before the Switch that was never much of a problem, but Nintendo's other studios and even many third party developers have always pushed much more demanding games than Gamefreak on their respective hardware.
In terms of this new game, Gamefreak probably needs help from another studio which has experience in designing open-world games. I hope they have Monoliftsoft helping them out like they did with Breath of the Wild. The closer the Pokemon come to the animals of Xenoblade Chronicles X in the wonder they inspire upon encountering them the better.