Kanto gave me more sci-fi versus fantasy vibes, honestly, and I do miss that old feeling. Stuff like creating a deformed evil/misunderstood clone of a cute and pure floating pink cat thing to use as a weapon, or creating the first ever digital Pokémon which can be evolved with an official update and black market malware, the Silph Co, Poké Balls feeling like a cutting-edge invention, taming vs befriending the wild beasts, the vaguely "grittier" edge to everything, the existence of actual ghosts, the focus on the PC, the Game Corner where you can literally buy Pokémon, a more realistic evil team, and so on. Johto felt like a purposeful contrast to Kanto in a way that strengthened the themes of both, but after that, the vibes slowly but surely started to shift.
The Poké Ball retcon was the point of no return for me, though.
