What does relevance even matter in a game like Smash?
A large number of characters on that roster are not relevant, or at least weren't before being added.
hadn't really shown up in any games prior to brawl since DK64
is still pretty much a dead franchise
literally appeared in ONE Zelda game, and is now a Smash staple
dead franchise before Brawl. Like, REALLY dead
unlike Falcon, Ness was even more obscure during this era due to EB being super niche and from a previous gen.
only got in due to fan demand
has only appeared in one game, least liked lord in the FE community. Like THE most irrelevant lord in FE, yet was still made DLC due to fan demand.
Seriously, the relevance argument is totally moot in Smash, if such weren't the case, the cast would be only Mario, Zelda, Pokemon, and AC. People only bring up relevance as some arbitrary way to back up a weak argument.
Plus, maybe you weren't alive during the N64, but before shooters and "open world" swept the scene, 3D platformers and collectathons were the hottest thing in gaming.
Guess which company was known for making the best, and making the best mascots for their games? Guess who was the face of collectathons and the N64?
I would say that certainly counts as making an impact, and being a gaming icon.
Kinda hypocritical to back up Mega Man, yet neglect the leaps made after.
EDIT:
Next time you people decide to use "relevance" as an argument, remember this video:
Over 90% of the cast, is NOT relevant. Having a game recently doesn't make a character relevant.