Seriously. I can't help but laugh when people are STILL trying to use "relevance" to discredit certain characters. Not only has Sakurai explicitly said that "relevance" isn't as crucial as moveset originality/uniqueness, but let's consider how many characters exist in Ultimate that were from dead franchises or not even from franchises at all:
-Ness
-Lucas
-Captain Falcon
-Ice Climbers
-Pit
-Dark Pit
-Palutena
-Little Mac
-ROB
-Wii Fit Trainer
-Duck Hunt
-Banjo Kazooie
-King K. Rool
-Mr. Game and Watch
-Pac Man?
Yeah, if someone can't fathom why a vastly original character from a successful Nintendo-Square collaboration deserves to get into Smash, there's really nothing anyone can do to help you. Simply bask in your ignorance and find another worthy character to support.
Ness: Mother is a cult classic in Japan and it wasn't dead by the times of 64, it even was going to get a N64 game.
Captain Falcon: F-Zero is a popular racing game and it wasn't dead when Smash 64 released.
Ice Climbers: NES retro pick that would bring a new gimmick
Pit: NES retro pick.
Dark Pit: Easy echo and came from a recent game.
Palutena: Uprising was new and very popular, Kid Icarus wasn't a dead franchise.
Little Mac: Punch Out! Always was a well liked game, Punch Out Wii wasn't too old.
ROB: It literally saved Nintendo.
Wii Fit Trainer: What? WFT was freakin big amongst casuals, it was one of the best sold Wii games.
Game and Watch: Another retro pick, but before even NES and from Nintendo's first Handheld ever.
Pac Man: Literally a gaming icon.