As we all know, Solos left when the Iron Crown event ended, however many people still want to play solo mode. Here are reasons why we should keep it!
1) It's fun
2) You don't have to depend on a squad. Most people for whatever reason ignores you when you need a revive, kirbies the items you need such as ammo, get themselves killed and they get mad at you for their mistakes, etc.
3) Teaming existed in Squads mode way before solo was a thing. It just wasn't common. You could actually fix it if you just have a mechanic that detects players moving together without fighting and then force them into a death match otherwise they both die.
4) The community asked for it so many times, in countless of threads
5) "Ranked" isn't even that good and Solo made the lack of that good.
6) Players getting annoyed with rude players, or simply ones who work best alone had a blast in solo
7) You're still getting threads to bring back solo and to keep it, why yeet it into oblivion when an event ended?
8) Fortnite has a variety of gamemodes, such as Squads of four, Duos, Solo, TDM, and multiple LTM such as Foodfight, sniper solo/duo, Disco Domination. The point is that Fortnite has "classic" gamemodes and they rotate more fun ones every other week. Fortnite even gotten salty when Apex came out and released a limited time trio gamemode.
I'm sure there's other reasons, but this is all I can think of right now!