Comparatively, Chrome controls the majority of consumer, business, and mobile, and the sole defense against a completely proprietary web platform is Safari being required on iOS.
IE actually had a much larger scale the Chrome does, as IE had 95% of the browser marketshare in 2004. Just because IE existed for years afterwards, despite only having a minuscule amount of marketshare, doesn't mean it wasn't defeated, either.
"Just because IE existed for years afterwards, despite only having a minuscule amount of marketshare, doesn't mean it wasn't defeated, either."
Lets go look at what actual numbers were:
2008:
IE: 69% Firefox: 26% Chrome: 0% Safari: 2-3%?
2009/2010 (Peak Firefox): IE: 55% Firefox: 32% Chrome: >4% Safari: <4%
I'm going off graphs rather than tables so the numbers are a bit off.
2012 (Peak safari): Firefox: 24% IE: 34% Chrome: 32%: Safari: 8%
2018 (Edge Becomes a chromium wrapper): Firefox: 12% IE: 6% Edge: 4% Chrome: 69% (Hey that's where IE was!) Safari: 3%
October 2021 (From chart on https://en.wikipedia.org/wiki/Usage_share_of_web_browsers) Firefox: 6-8% IE: / Edge: 12% Chrome: 73% Safari: 3% Actually just chrome: 85%
Opening up iOS is not going to magically make Firefox popularity boom, any more than android, if people install a different browser it will be chrome.
And once that is possible, Google will push Chrome on all of their properties. Just like they do on desktop.
To reinforce the amount of power google has. No other browser managed to kill IE6, not even IE>6. Then one day Google literally just decided that they would stop support IE6 on YouTube. Every person who came to YouTube with IE6 was greeted with “your browser is not supported. Update to a newer one. Chrome is a browser by Google that is designed from the ground up for security and performance. You can get it here”.
They rapidly rolled that change to their other properties, and by the power of controlling all the largest and most popular sites on the web they killed IE6 in like 6 months.
The entire existence of other browsers is dependent on what Google does with their dominance in web content.
I don’t know about Firefox, but in Safari when I go to pretty much any google property it’s aggressively marketing Chrome, and reasonably high % of the time. Google.com itself, possibly 100% of the time?
At the same time google has actively pushed back against most privacy efforts on the web, regularly nominates new standards that have the sole purpose of supporting their advertising business, etc
Besides, Apple maintains Safari the way it does for no other reason than for disallowing people from building more functional open web apps so that to reach iOS users, one has to build native iOS apps.