Republicans, in one of the more moronic takes of the election season, say that if Biden is too old to run for office, then he's too old to hold the office and should resign.
It's mostly newer programmers who remember how to design a complex algorithm on the fly because these are taught in college and then used as study tools to land a job. Over the past decade or so, software companies started requiring these algorithm tests during interviews. More senior developers don't want to go back and study for something that really won't do much to help them at all, except in interviews.
I think it comes more down to the fact that companies want an easy way to get butts in seats at the lowest cost possible. Including these silly tests eliminates most of your candidates, making your job of filling those seats much easier. And, conveniently enough, the people who pass tend to cost less! Imagine that.
I also think they want more gullible, naive and pliable workers. People that won't ask any difficult questions and go along with all the happy horseshit that corps like to sling. These tend to be younger.