> At some point in history, people stopped worrying about not understanding compilers
> This part is misleading too
Not in the least. Interpreting that to mean "all people stopped worrying" is deliberate misinterpretation.
Saying people who don't optimize for performance don't have technical excellence is just like saying people who don't get all of their program to fit into 32kb don't have technical excellence.
Yes it requires skills to get a program to run in such a small amount of space, just like it takes skill to perform detailed performance optimizations. But in either case if that's not your job you're wasting time and someone else's time, even if it makes you happy to do so.
A product is designed to serve a purpose, if instead of working on that purpose is developer is squeezing out a few additional cycles of perf or a few additional kb of memory they have the wrong priorities.
No that doesn't mean go to the other extreme, but choosing to not spending unnecessary time on performance or size optimization is entirely unrelated to technical excellence. And any senior engineer knows this.
At some point in history, people stopped worrying about not understanding compilers
This part is misleading too -- I would say there is a renaissance in compiler technology now. For the first 10 years of my career I heard little about compilers, but in the last 10, JS Engines like v8 and Spidermonkey, and AOT compiler tech like LLVM and MLIR have changed that.
The overall historical trend is that computing is getting used a lot more. So you have growth on both ends: more people using high level languages, and more people caring about performance.
It's not either/or -- that's a misleading way of thinking about it. The trend is more "spread", not everyone going "up" the stack. There will always be more people up the stack because lower layers inherently provide leverage, but that doesn't mean the lower layers don't exist or aren't relevant.
And lots of people migrate "down" the stack during their careers -- generally people who are trying to build something novel "up stack" and can't do it with what exists "down there".