Great points.
Though I believe algorithmic knowledge is a lot more practical than people give it credit for. I'm not talking about crazy graph searches, or implementing A* in ASM.
Are you going to be efficiently searching strings, or reordering arrays, full time? Probably not, but you will likely come across a time where you will need to think about the consequences of your design, even in a simple crud web-app. And that stuff is important.
Algorithmic testing has real practical implication if the role requires it, which a subset of the engineers at the aforementioned companies will use.
The other practical implication is standardization of the interview process, rooted around an academic background in computer science. It's easy to test whether someone knows a "fundamental" (whether it's actually fundamental to the job is another question) cs data structure or algorithm.
The idea is, interview for square pegs, since it is easier to measure the quality of that particular shape at scale. If there is a high-quality peg that happens not to be a square, it is a loss that the system is willing to accept, provided that a large enough % of the good candidates are squares.