Something I find funny about this is that this stuff has been advice for decades and even though the reasoning for the advice never made any sense, people just went along with it and no one ever tested it.
See also https://danluu.com/keyboard-v-mouse/, https://danluu.com/bad-decisions/, etc., as well as most conventional wisdom in tech. There's tons of stuff that people do for reasons that are fairly obviously wrong and almost no one questions the reasoning or runs the tests to see if what everyone is doing is wrong.