I'm pretty radical on this topic but for me cognitive load is good, you are making your neurons work and keep synapses in place where they matter (at least for your job). I totally accept writing down doc or howto to make doing some action in future easier and reduce that cognitive load, but using AI agent IMO is like going to bike in the mountain with an electrical bike.
Yes, you keep seeing the wonderful vistas but you are not really training your legs.
By using LLMs to do some of the stuff I have long gotten over, I have a bit more mental energy to tackle new problems I wouldn't have previously.
As well LLMs just aren't actually that competent yet, so it's not like devs are completely hands off. Since I barely do boilerplate as I work across legacy projects, there's no way Claude Code today is writing half my code.