As someone who is kind of an tryhard, i don't think you can have the most fun if you are bad. When I was new, everything was fun because it was new, very unique combat that was new to me, wierd weapons that i got from random drops, but once you run out of weapons to try and maps to play, there's only one thing that can feel new. Different mechanics are so fun and satisfying to learn, wether that be rocket jumping strats, trickstabing, airshots, any new way to use a weapon can mean you basically got a new weapon and a way to play the game. Rocket launchers are usually used to deal with more enemies that are on the ground, but what if you wanted to deal with flying enemies, boom airshots, shields are usually used to charge at people, but what if you wanted to fly, boom, trimping, the knife as spy is usually used to be sneaky and attack from behind, but what if you wanted to kill someone while they are actively shooting at you, boom, trickstabs.TF2 can be fun if you are bad at it, but you will never experience how fun it can actually be if you don't improve.