So...
I have ideas.
If smash was to be rebooted.
1. Cut the roster down. Sm4sh and ultimate's rosters were too crazy. Cut them down to only the most important characters. Add a small amount of newcomers.
2. Cut stage amount in half. Add a few new ones.
3. Cut assist trophies. One summoning item gets the match more intense enough.
4. Have a smaller number of items.
5. Bring back trophies. Make them easier to collect, and just scrap challenges and event matches completely.
6. Focus on fun gameplay, limit down the large amount of modes, and just keep a few things from the vault, home run contest, all-star, and classic modes.
7. Get rid of all the fancy techniques. Make it easy for everyone.
That's all I have to say.
So yah, expanding on this, roster will be made.
Here we are. All third parties are cut. It is a Nintendo fighting game, so why clog it up with useless indies?
Mario:





:, as well as Goomba and Toad as newcomers. Goomba is the enemy rep while Toad was added in as he is incredibly known. I kept the main stars and kept Daisy (she was on the brink of being cut) but kept her due to her being more known than bowser jr per say.
Dk:


, The main character and villain. Diddy was cut because he was a side character and unless Dixie gets in, he's staying cut.
Yoshi:

, and Poochy as a newcomer. Poochy is basically the secondary main character of Yoshi due to Baby Mario not appearing in a Yoshi game since Yoshi's Island Ds. You could say Kamek over Poochy, but he's my choice.
Wario:

, nothing else to say here.
Zelda:



, Ganon as a transform,

. I kept Link and Zelda as they are the main stars. Ganondorf has Ganon so they are the main villain, while Toon Link is the main character of a lot of Zelda games these days. Young Link was cut due to only having two appearances, same with Sheik.
Pokémon:




, and Melmetal as a newcomer. Pokémon was hard in the sense most veterans are much loved. Incineroar was cut because he is way less popular smash wise than the others. Greninja was kept to represent the starters. Pokémon Trainer is the main character so he was obviously kept. Pikachu and Jigglypuff are icons by this point. It was a tough choice whether or not to cut Mewtwo, but since Melmetal has been getting a lot more attention than other mythicals, he was added to replace Mewtwo and represent the other legendaries and mythicals. Lucario was cut, but I forgot my own reason for it lol.
Metroid:



, Samus is in as she is the main character, Ridley as the main villain, and Dark Samus to represent the prime series. Zero was cut due to only two major appearances within Metroid, Zero Mission and Other M.
Kirby:


,with Dark Matter as a newcomer. Kirby and Dedede are the most known Kirby characters, while Dark Matter was added as a villain rep, they are the only villains who are actually still a villain that isn't the size of the planet or whatever.
Star Fox:


, Hero and Villain rep, with Falco cut due to Slippy and Peppy not being in, it feels unfair to them.
F-Zero:

Mother:

, with Porky as a newcomer. Hero and Villain reps. Lucas was cut because it felt like disrespect to Ninten.
Other: Basically the franchise which have always had one rep.







, with Starfy and Chibi-Robo as newcomers. The Mii's were kept due to being the technical mascots of the wii, R.O.B due to his importance to stopping the gaming crash of 83, Game and Watch due to representing Nintendo's oldest handheld, Duck Hunt, because if the game's success, and Little Mac to represent Punch-Out!!. Starfy and Chibi-Robo were added due to being decently known Nintendo franchises.
Fire Emblem:



, Marth because Marth, Ike because of his importance within fire emblem, and Robin to represent awakening, the game that saved fire emblem from being cancelled.
Kid Icarus:


, the two main characters.
Pikmin:


, Olimar as the main character, with Alph representing Pikmin 3's crew.
Animal Crossing:

, with Tom Nook as a newcomer. Villager is the main protagonist, while Tom Nook is the most important villager within animal crossing.
Xenoblade Chronicles:

, with Rex as a newcomer. Shulk is the main character of the first game, while Rex is the main character of the second.
Splatoon:

, due to being one of Nintendo's most successful new franchises.
There we are.