Let's say you have a brand new computer, and want to download nVidia drivers. Fire up your brand new computer, search for "nvidia drivers" using Bing.... and the first results are all ads for extremely scummy adware. (It's also hilarious when you search for "chrome download" when Edge begs you not to, and including when you click through, but that's a story for another time :)).
Obviously for this audience. But two of my buddies didn't even know such things existed and were truly grateful when I introduced uBO/Privacy Badger to them.
Compatible against what? The web standards or Google Chrome?
Unless someone pays me to open them (read: I need them to do work), then I do keep an instance of Chrome around. But only if there is no other choice.
User-agent sniffing[1] and it is a webdev smell. I acknowledge that this is true, but I admit being bummed that we didn't win the war to use web standards.
I got a full screen cookie consent popup, a location permission popup, and ads were everywhere on the screen. Must have been 50% of screen space for the top part of the page. It's absurd!
Also, most people care much more about "it simply works", and that is Chrome. Firefox is neither preinstalled nor as compatible as Chrome (nor as fast or user friendly). There's already a lot of popups like "this site works best in Chrome".