> Besides, IE was closed source and WebKIt is open source. So are all other engines. And web standards are really a thing now.
Even today, this doesn't mean much if Apple decides to ignore web standards that are harmful to their business model. Web Notifications were implemented by Safari Desktop, Chrome Desktop and Firefox Desktop[0] in 2012 - and Safari Mobile in 2023. That's 9 years that a pretty useful and important API couldn't be relied on by PWAs. And this is just one of many examples.
This has a real effect on what technologies developers can actually use, which is fairly similar to the effect IE6 had on newer APIs during its time.
[0]: Chrome & Firefox desktop because I can't find a way to see historical dates for mobile on caniuse - but it was around that time, or a bit later, for mobile as well