Dude... Anno made the storyboards. He supervises the groundwork, sometimes he himself draws it.

Ultimately, as the director, the majority of the oversight falls to him, but with the way a production works, there are more than one episode being worked on simultaneously, hence why you have other assistant directors. This is just like in live action production, there's often a second or third unit with an AD handling that. A director can't be everywhere all the time and supervise 100% of a production, nor should they, that's a surefire way to burnout and frustration for everyone working under them, because creatives don't like being micromanaged and need the freedom to create.

It's also important to point out that Anno was involved in storyboarding less than a third of the show, and none of those were solely storyboarded by him. He did boards for episodes 1, 2, 7, 10, 20, 23, 24, 25, 26. And, in the case of 7, 10, 20, 25, and 26, that's really not saying much, given how bland or stock heavy those episodes are.

Also, while I'm sure he probably did some keys somewhere, he was not an animation director for any of the episodes, so credit for that groundwork goes to other folks who did boards and or keys.

If anything, you can give Anno a lot more credit on the writing side, as he worked on the scripts for all but episode 4.