more than just good animation i think what invincible really lacks is good character acting. A lot of times characters just feel so Motionless and default to "standard" movements that feel really plain after a while
my best friend in graduate school was a gay historian (in both meanings) and always shared the more colorful things he found in the archives with me. and honestly, i think most modern fujos would kill themselves if they knew how gay men were moving before the AIDS crisis.