They say writing engages more of the brain and helps us to remember what's written more than if we just read it, or copy and paste.

When you say it's easier to go manual, it seems you're talking about learning retention. And you're right.

But seniors have learned enough that they're able to iterate quickly with AI.

They know how to organize their work, manage change, tasks. They know how to break a problem down into smaller pieces. They're aware of context windows, token cost, estimated task lengths, etc. And most importantly, and to your point about ease: they have less to learn so retention isn't an issue.

I have no opinion about whether we're in a good or bad situation, just making arguments from the toilet really.