I had made the observation that I increasingly started to "garbage collect" all the small stuff that was basically akin to muscle memory.

To me it's still worth it to keep up some level of "language lawyering" in my head as I had been practicing the craft of it all through daily application for many years. There was IMHO no reason to throw that away over time.

I only use LLMs for new stuff / learning, though even there I'm still conflicted if reading the manual / spec like we used to isn't more efficient in the long run?

Again, retaining of basics / primitives but also maybe better mental modelling by going deep head-first and on my own brain cycles?

TL;DR sharing the concerns; still conflicted in how useful LLMs are for programmers; maybe learning? Maybe interfacing for general utility outside of creative tasks is the main value? IDK...