>eyelander, the sandman or the base jumper
Eyelander is cool af and carry building is a core part of MOBAs. I'd love it if the eyelander was a core part of tf2 cause it would do a lot of cool shit. It'd make momentum more important but also increase the gamesense required because demo situationally would go from incredibly high value pick to mostly worthless use of a sac
Sandman is pretty shit but the ball mechanic isn't inherently flawed. Stuns are bad but honestly with the right mechanic behind it it could be cool. Something like "can't cap for x seconds" or something that makes it a team support weapon would be kinda cool
Base jumper allows more movement options which is good for tf2
tbh it sounds like you have a concrete notion of what TF2 is and refuse to let anything else be "esport" but that's honestly myopic af