I don't like "shaming" people for not learning "fundamentals", and I believe people should learn whatever they want to at their own pace, but since you asked --
Sometimes you run into bugs (or leaky abstractions) that force you to go down a couple layers. Perhaps you run into a bug in the C/C++ code of your language's compiler. Sometimes a dependency (written in C of course) of your stack gets a nasty CVE and you need to figure out the implications (often being able to read the patch will help). Ever heard of "Meltdown" and "Spectre"? Those were bugs in CPU design which require understanding of how low level operations work.
In junior roles nobody will bother you with these questions, but senior devs are expected to know how to understand and deal with these issues if relevant, even if they're normally using a super high level language, because they don't exist in a vacuum, they depend on these low level things to form the whole "stack" so to speak.
In terms of education in schools, time is limited, so there's obviously a need to choose the most relevant topics to focus on. Learning fundamentals has always been at least occasionally useful though. I mean, you could probably do 99% of your job without knowing this stuff and you'll probably even have a great career. Personally, I just hate to feel ignorant about the things I do for a living...
Sometimes you run into bugs (or leaky abstractions) that force you to go down a couple layers. Perhaps you run into a bug in the C/C++ code of your language's compiler. Sometimes a dependency (written in C of course) of your stack gets a nasty CVE and you need to figure out the implications (often being able to read the patch will help). Ever heard of "Meltdown" and "Spectre"? Those were bugs in CPU design which require understanding of how low level operations work.
In junior roles nobody will bother you with these questions, but senior devs are expected to know how to understand and deal with these issues if relevant, even if they're normally using a super high level language, because they don't exist in a vacuum, they depend on these low level things to form the whole "stack" so to speak.
In terms of education in schools, time is limited, so there's obviously a need to choose the most relevant topics to focus on. Learning fundamentals has always been at least occasionally useful though. I mean, you could probably do 99% of your job without knowing this stuff and you'll probably even have a great career. Personally, I just hate to feel ignorant about the things I do for a living...