Nearly all of the biggest competitive multiplayer/esports genres of today started as mods.
- CS (half-life mod) -> Competitive tactical shooters (CS:GO, Valorant)
- Dota (War3 mod) -> MOBAs (Dota 2, LoL, Smite)
- Team Fortress (Quake mod) -> Hero Shooters (TF2, Overwatch)
- DayZ (Arma 2 mod) -> Survival FPS (Rust, Ark)
- Battle Royal Mods (like Hunger Games for Minecraft or BR for Arma 2) -> Battle Royal (Fortnite, PUBG)
Why?
Multiplayer games require other players! Mods generally come with a 'built-in' playerbase and a very low barrier for entry. The vast majority of innovation in the multiplayer space comes from mods, since trying something new as a commercial title has a huge risk of never establishing a big enough playerbase and just dying out before anyone tries it.
"Hähnchen geht, ne?"