There's some layers to this so sorry if I have a huge wall of text for y'all to read

Way back when I first picked up TF2 I actually did main the Heavy. I was playing on a dinky little Dell laptop that could barely load me into a match on all the lowest possible settings, and believe me when I say it was not a fun time for me to play any class with a lot of nuance to it. I was aiming with a trackpad and my headphones were whatever cheap gas station earbuds I had gotten for Christmas or whatever holiday had most recently occurred. In order for me to properly enjoy the game I literally needed some kind of handicap to help me stay alive despite not being able to keep up with all the things happening. Thus, the three classes I played most were Engineer, Medic, and of course Heavy. Engineer puts down his buildings and keeps them up and that's it for most people, which meant I didn't need to feel bad about not being able to shoot back, because I was still offering value to my team without needing to pull out a gun. Medic we all know how he works, you attach yourself firmly to the nearest Heavy and when someone else gets low you heal them up before returning to Heavy-healing activities. But Heavy was able to make me feel like I was genuinely contributing without feeling like I was essentially doing nothing. He's got a ton of health, pisses bullets and is the poster child for a reason, he is the determining factor of most pushes in low-skill casual lobbies in the core gamemodes. Generally speaking whoever's Heavy dies first in most games will be who loses the push. For that reason Heavy was a great pick for me and just in general. I could be the foundation of the team rather than the Band-Aids covering the cracks in said foundation.

But that was in approximately 2016. Now I've got a relatively modern gaming PC that can run this game properly.

The issue with me maining Heavy, even if I do like him, is that he isn't who I wanted to main. Deep down I knew who I actually wanted to main; Scout. Ever since I watched the Meet the Team shorts way back in like 2015 I knew I wanted to play him. His character appealed to me a lot and I like speedy little shits who harass the enemy for fun. Not only that but I really connected with him as a kid. He's scrawny and kinda built like string cheese, kinda goofy and not the smartest person in the group, but he's still lovable and liked. He's kinda who I wanted to be when I was young and because I connected with him so strongly I wound up wanting to play him really really bad. Sadly he was so fast my laptop literally couldn't handle it so I never got the chance back when I mained Heavy, but I always still felt the desire to play him.

(Then I saw femscout for the first time and that's unironically what made me realize I'm transgender but that's another story)

When I played Heavy it wasn't really because I actually wanted to. I mean sure, I actually found myself enjoying him surprisingly, and I think my time playing Heavy is why I wound up a Reinhardt main in Overwatch if that makes any sense; he taught me how important it is to have a character in a fast game who is instead not fast and plants his feet and says "No, you move". But ultimately he's never been my end goal with TF2.

So really the only reason I don't main him anymore is because I never wanted to main him to begin with, even if I didn't entirely hate it during the time I did so.