For me, easy is something that a person of average skill in that domain can do and that the top 20ish% person in that domain can do with their eyes closed.
I have a masters in CS, I know all of the words and stuff in your essay. I have been programming python for a while. I would most definitely need to study up on graph algos, implementing sorting algos, dynamic programming, etc. Then refresh my big-O notation as well. Unless you are doing it everyday, this stuff ain't simple or easy to master to the level of being able to code it up during a 45 min online session.
I can easily see 2-3 weeks of full time studying for myself to even be minimally ready to code up a BFS search in python, as part of a larger problem, in python, in 45 minutes, while writing an example down, while writing a test case, while talking out loud.
I think this essay understates how difficult the coding test screenings can be. I do agree that it is not necessary to memorize obscure algorithms - second year data structures and algorithms will do. But (based on my experience) the progress you need to make in workable code in 45 minutes at s whiteboard id too great to refer to any of this as a “simple coding test”. I know some might view this as a quibble around semantics, and “simple” is subjective. But words have meaning and we have to draw the line somewhere. I maintain that this is not simple for a reasonable definition if simple.
This is easily remedied since I can be exact: designated “hard” questions from Cracking the coding interview are fair game, and you are expected to make substantial coding progress at the white board in 45 min.
I’d like to wrap up by coming back to my first point - excellent essay, worth bookmarking and reading in full.