When you compare it to Ultimate, the OG smash is kinda bad.

Well yes of course its not as good it was released in 1999 that's like saying "the Pokémon games on the Gameboy aren't as good as Pokémon Sword and Pokémon Shield" so I really don't understand your thought process here...

Pokemon wasn't always 3d. Smash was.

yes but that still even adds to the point and what world isn't Pokémon 3d its always been a 3d/top view open world game. Smash bros has evolved over time Pokémon has stayed more or less the same. You really need to get more facts not to be rude and smash isn't even 3d? Its a 2 and a half D fighting game

Super Smash Bros 64 probably has some downsides like graphics, but overall I think it's a good game.

it is a good game but has terrible graphics and is extremely broken

yeah the stun is insane and the hitboxes are WAY bigger than they should be