amund: I don't understand why 16:9 got so popular
I presume it was because DVD-movies, hence TVs, hence gaming consoles, used it? So PC eventually kinda had to follow suit.
PC has had to fight with two objectives which preferred opposite aspect ratios. In the past desktop and office programs would have usually preferred narrower and higher aspect ratios, which is probably why we used to have those higher 5:4 aspect ratio monitors for awhile (ie. they were narrower than even 4:3 TVs and monitors), and monitors that let you tilt the screen on its side so that it is 3:4. Easier to edit Word documents that way I guess.
But at the same time, movies and console games preferred wider 16:9 aspect ratio, so it kinda made sense PC (gaming) also went that way.
For modern desktop office work, I think wider is better nowadays, as most people want more desktop space sideways, which is why people have dual monitors. I've been thinking of replacing my two 16:9 monitors at work with bigger and much wider single monitor.
However, for laptops I don't think wider than 16:9 makes much sense because then the laptops just start becoming... too wide (the keyboard and case).