Some Pokemon games haven't looked so good, but all the Tears of the Kingdom footage shown so far looks at least as smooth and detailed as Breath of the Wild… but Breath of the Wild came out in 2017.

Source: https://www.cnet.com/tech/gaming/the-legend-of-zelda-tears-of-the-kingdom-what-to-know-before-playing/

The surprise/wonder trades brought a whole new way of playing the core series Pokemon games, as it was now possible to essentially swap out the mundane route encounters with a random Pokemon being traded away across the ether.

Source: https://gamerant.com/pokemon-best-challenges-make-games-harder/