The problem is it only works for a certain personality and thinking type that can do that under pressure in front of an interviewer. Most of us who have been in the industry for a while solve algorithm problems by working in an editor or REPL, and do so in a solitary way, with time to pause and think.
The Google-style process (that so many people copied) acts as if the ability to do that kind of thinking under time pressure and in front of a generally-elitist interviewer is some kind of marker of the ability to work on the job. It isn't.
Plus I worked at Google for a decade and the amount of times I had to do actual algorithm/data structure fundamental stuff was about 0. 90% of Googlers are wiring existing crap together, and if they stray outside of that they'll get spanked in a code review anyways.
The Google-style process (that so many people copied) acts as if the ability to do that kind of thinking under time pressure and in front of a generally-elitist interviewer is some kind of marker of the ability to work on the job. It isn't.
Plus I worked at Google for a decade and the amount of times I had to do actual algorithm/data structure fundamental stuff was about 0. 90% of Googlers are wiring existing crap together, and if they stray outside of that they'll get spanked in a code review anyways.