First of all, high IQ doesn't necessarily mean you are intelligent being. You are just a good pattern solver and logical thinker and you can actually improve your score with practice or with kind of work you are doing (programming, math, physics, etc). Intelligence is much more than having a high IQ score.

Second: browser usage is a preference thing. There was a time when IE was dominant browser, and like Chrome nowdays, IE had popularity vote back then. With Edge we actually have a decent browser, but it still lacks some things. I personally hate Google Chrome. It's probably the fastest browser of them all, but that comes with a price. It's consuming way too much proc. power and ram as it should. And I see some privacy issues with usage also. My weapon of choice nowadays would be Opera. I prefer minimalistic design, well balanced speed and performance. It's still based on Chromium though, but that is not a bad thing. Opera is not perfect either. I use most of these browsers on daily basis, because of nature of my job.

There are people who are really smart that I know (with their pHd-s and stuff), who still use IE nowdays. People prefer Chrome because it's simple, it's faster, but does that make them smarter? Do they really do their research before choosing browser? They probably just go with the mainstream flow like everybody else.