Because in Gen 4 especially, there were WAY too many HMs, so you’d need an HM for all your team plus a HM slave.
Only good HMs in Gen 4 were:
Surf (Special attackers)
Waterfall (Physical attackers)
Strength (As a Return alt, for non-STAB and Pokémon that don’t learn Body Slam)
Fly (Good for main game, as it sucks competitively)
reshikrom64
Of all the things you could use a Mew for, why an HM slave?
Blob Takeshi
Because in Gen 4 especially, there were WAY too many HMs, so you’d need an HM for all your team plus a HM slave.
Only good HMs in Gen 4 were:
Surf (Special attackers)
Waterfall (Physical attackers)
Strength (As a Return alt, for non-STAB and Pokémon that don’t learn Body Slam)
Fly (Good for main game, as it sucks competitively)
Blob Takeshi
First Mew since Holon Phantoms.
Mantidactyle
Nope, Secret Wonders
Derpinator
Careful or Mew will CUT you!