I think as an existing expert in my field (robot devops) what I feel most strongly is not that I'm losing my skills but rather than I'm losing my nerve.
Like, problems that I would previously dig into on my own, poking at this and that log file to try to understand what happened to get a system into a particular state, now claude is mediating most of those kinds of interactions and it is the one doing the first pass surfacing of "okay I discovered X, Y, and Z things that are hinky, and I'm not totally sure yet what this all means, but let's look together."
Nowadays I feel almost naked looking at a terminal where I'm typing each character myself. A lot of the old instincts around tab completion and grepping through the --help output of every tool, all that stuff has atrophied somewhat. Maybe that is genuine skill decline?
I think this is a really important idea. Good problem solvers, in general, are people who are prepared to go in and poke around, to see what happens when you disable this or add that.
The only way I've found to make juniors develop that instinct is to make them do it until it comes naturally--to continually demand they verify their assumptions, test out theories while debugging. If you don't practice being comfortable with the unfamiliar, you lose the knack.
It's fine, of course, to lose the knack to AI, as long as you'll never need to solve a problem the AI can't (or can't access). I don't think that's a good assumption for everyone to make.