Just for the record, other people at 1960s Marvel besides Jack Kirby knew how to draw, too.
Which isn't to rip Kirby at all, but sometimes the (justified) worshipful drumbeat drowns out the accomplishments of others.
Take, for example, the Kirby/Dick Ayers cover for Avengers #24 (1966):
It's a fine cover, no argument...but when faced with a similar situation for the cover of Avengers #44 (1967), John Buscema & Vince Colletta turned it up to 11:
That, my friends, is a cover!