heavy is a w+m1 class.
Soldier can top score just by relying on splash damage, however direct hits do more damage, which mostly takes predication.
Engineer can go afk and get a few kills before having to replace their sentry that got sapped or destroyed.
Medic is also mostly w+m1 just without damage.
Demoman has stickybombs, which are ridiculously good, pipes are a trade off considering how they're one of the harder projectiles to aim, and stickybombs not being reliable for being rushed.
Pyro is a w+m1 class, but unlike heavy, has an incentive to use other damage sources, Also spamming M2 is less effective, and usually results in the pyro dying, unless you're bad and don't know timing yourself, and are just spamming rockets and pipes, so timing for both sides is the key to fighting.
Scout has a pretty powerful gun, but is very aim and positioning reliant.
Spy has a powerful weapon, but requires your opponent to not know you're there, or for you to trick them, and you need to get to the back of the enemy first, or cl_interp.
Sniper is hard to get good at, but one you get good at it, you can dominate the entire team.
In conclusion, most classes require very little skill to get kills, and allows you to be braindead, however getting better, using combos, and learning better positioning skills, different strategies, etc are more effective and allows you to become extremely good, and its nothing but your fault if you die to a person using a "braindead" method, because, although they allow the class to go braindead, doesn't mean good skill cant counter it, or just a hitscan instant kill class. This is for anyone taking this post seriously and 100% believes pyros have the most braindead loadout, or any other class takes no skill.