No they don't. Employers heard that Google asks questions like these, and Google is worth eleventy skrillion dollars, so if we ask the questions Google asks we'll be worth eleventy skrillion dollars too!
In much the same way, last decade everybody knew Microsoft asked riddles, and Microsoft was worth more money than anyone could imagine, so obviously asking riddles is the way to end up worth more money than anyone can imagine.
It's basically this comic, but implemented in tech interviews instead of in schooling:
http://smbc-comics.com/index.php?id=3978
Meanwhile the only reason these things seem to "work" for Google et al. is that they get so many applicants they can afford to turn down huge numbers of perfectly intelligent, perfectly-qualified people who might not do so well on an algorithms pop quiz. And at the same time they've made the process easy to game: you can literally get books of Google-style interview questions, study them, and then pass tech interviews without the underlying knowledge/experience the questions are allegedly selecting for.
I just wonder which company will be the next big breakout hit and what irrelevant thing they'll do in interviews that everyone will hurry to nod their heads and sagely agree with as a great indicator of the kinds of things "employers want".