•With current limitations in ammo size, a human loader is still faster. I've seen HEAT chambered in 2.08 Seconds in MOPP 4.

•Your average loader might get tired after a dozen rounds, the rare event you're in a cold war goes hot Fulda Gap esque combat environment rich with hundreds of targets means this is largely irrelevant anyway.

•Your tank gun isn't much different than any other gun, rounds still fail to fire, extract, and feed. Manual cycling of the breech is easier without an autoloader.

•a lot of autoloaders either have to segment their ammunition into charge+projectile, or limit cartridge lengths to an extent your kinetic penetrator doesn't have enough mass to be effrctive against other MBTs. (Challenger II has this problem even though they don't have an autoloader lol)

•the likelihood of a manual fed MBT turning its turret into a flying frying pan is virtually non existent.