Right! I haven't gotten to play that game yet, but I heard the impact the game made when it was revealed at the end that there is an extra 8 gyms. Its definitely on my bucket list along with Golden Sun and Sacred Stones
On another note, I remember how big the world felt in Diamond and Pearl, and being really shocked how small everything felt in comparison in Sword and Shield ( However I did find SW/SH's world building and the villains motivation refreshing).
Also Pokémon is notorious for some absolute fantastic post game content, its a shame nowadays that it's not in the base game.