> Pre-Arduino, learning electronics wasn't more profound. It was just less accessible.
This absolutely matches my experience. I was very interested in electronics growing up in the 80s. I took everything apart (occasionally without breaking it), I had those spring terminal "200 in 1" kits, a crappy soldering iron, and tons of enthusiasm and energy to channel into it. But I very quickly hit a wall trying to understand analog circuits, and I gave up (and redirected my interest to computers).
Some of it could be the limited information I had access to, in a small town, pre-Internet. There was a lot of math, and this was when I was like 8-10 years old, so it was way over my head. But I tried several times over the following decades to get back into it, and I just couldn't find a way in that connected with me.
The point of all of this is that in 2012 I stumbled across an Arduino kit and everything changed. Now I could apply the digital logic and programming concepts I understood to make things that did stuff. I rediscovered my interest in electronics, and the part that's most relevant here is that because it was accessible and fun, it gave me an on ramp to start to explore the analog world a bit more. The concepts began to make sense and build on each other as I developed an intuition for how they worked, and now I feel reasonably comfortable with analog circuits.
So I don't see it so much as nobody is going to learn other things because they can just throw a MCU at it, I think it's a great way to get started and then go on to develop a more thorough understanding of electronics (if that's your thing).