PewDiePie made a video on why he installed Linux and explained why everyone should do it too. Due to his number of followers, this might be the year of the Linux Desktop? Hooray?
Why should we care what a multi-million dollar youtuber uses for an OS? He can afford to build computers for each OS at their highest specs in his range. I'm not going to be brow-beaten by this chump either.
Do you think celebrities aren't influential? I mean that's how Trump became President. He had zero prior political experience.
Has PewDiePie done anything significant to help make a better change?
Doesn't matter if it's better or worse, the point is that he's influential. He's one of the largest YouTubers on the platform. But regardless, I would say that yes, he has, as in the video in the OP. Not just a Linux video, but a positive and comprehensive one.
That's not what Linux is at all. One of the main advantages of Linux is it can run on bad PCs, look up Raspberri Pis that have 4GB RAM and function flawlessly with Linux(I have one).
I've got a 14-year-old Toshiba that I used in college that runs a weird variant of Ubuntu called Kumander (it's designed specifically to look and feel like Windows 7, which I think is properly nostalgic for the hardware). As long as you don't expect the battery to last more than an hour (which about par for the course for a laptop from then) it's perfectly serviceable as a SOHO-type machine.
Also it can double as a self-defense weapon cause it weighs like 10 lbs.