Gen 4 and the phys/spec split is when types stopped being descriptive and started being turned into generic elemental "energy".
Before we had Flamethrower, Vinewhip, Metal Claw - stuff that was simple but intuitively made sense. With gen 4 and onwards we got stuff like Energy Ball, Flash Cannon, Flare Blitz, Dark Pulse, Aura Sphere, Focus Blast, Dragon Pulse etc. Many new moves just became generic colour coded blob attacks because we need a physical and a special version of every type. So in the anime everything became the same colour coded bullshit.
Gen 1 had stuff like Fire Punch, Ice Punch, Thunder Punch and they later added Shadow Ball, which was pretty stupid, but the punches atleast followed a common theme and Shadow Ball was a necessary new ghost move (even if it isn't particularly inventive).
Moves stopped being inane abilities of Pokemon physiology and leant more into Pokemon being animalistic wizards where everyone could just summon every colour and turn it into a blast attack (or alternatively a colour coded tackle).
