Having a bunch of basic, generally useful algorithms in recent memory does save a lot of time on the "general solution" side when you're working in a new milieu. (That saved time then gets consumed trying to find, configure, and tune anything in an unfamiliar cloud environment, but that's another kettle of fish).
Knowing how to solve the ten or twenty most common CS interview questions is not an indicator of possessing "top knowledge". It's an indicator that someone studied the cheat sheet to big tech interviews, and that's all.
The coding problems are part of the interview, but they're not the entirety of the interview. You can't pass a FAANG interview by cramming CS questions, unless you're maybe applying for a new grad position where previous work experience isn't factored in very much.
Of course, if a company is just building the stereotypical basic CRUD app to serve a maximum of 10K users total and maybe 10 per minute at peak, this probably doesn’t matter much.
However, companies that pay top dollar expect candidates with top knowledge, and that’s fair IMO.