But a big yes for still typing code by hand, and not leaving it to the llm. Except it has to be the code generated by your brain.
That is what will create new neurons and new connections, which is what will keep away the cognitive decline.
And the constraint of not having to use llms will enhance creativity.
Actually, the constraints llms add to your code are more in number than the former. llms code in only the specific ways they've been trained on. So you won't ever come across of other ways.
Off the top of my head.. here's RubyQuiz.com [0] which I came across when I was learning ruby more than a decade ago. Looking at the many user-submitted solutions (you have to download the zip file!) you'll see completely different ways the problems were solved.
Sure, many won't be deemed efficient or standard by today's llm or rubocop checks, but looking at their code.. and retyping them and seeing them work.. was crucial in how I was able to think in Ruby for solving coding problems.
I did the same with Go too, with the "learn go with tests" guide [1].
[0] - http://rubyquiz.com/