>>29385516They're literally just roadblocks to make sure the player doesn't explore too far without a certain number of badges. Carrying an HM slave is as "challenging" and "strategic" as carrying a key to open a door.
Starting at Gen 3, when they could no longer even pretend there was a hardware limitation, it would've been so much more practical to just give pokémon those out-of-battle functions depending on which HM moves they could learn, because YOU STILL NEED A CERTAIN NUMBER OF BADGES ANYWAY.
