The situation with Safari is nothing like what we had back in the IE6 days. It was like developing for multiple platforms, not just a multiple browsers.
Thats not to say Safari isn’t dragging it’s heals, but it looks like Apple are finally ramping up development speed. I gather they have been expanding the Safari dev team, and the latest announcements at WWDC look really good.
I actually use Safari as my primary browser, I prefer it (as a user) to Chrome. Although for debugging Chrome dev tools are better, I probably open it 2-3 times a day to check stuff, but never leave it running.
In at least one way, it's worse. You have a large percentage of users (everyone on iOS) who is stuck using a single rendering engine (Safari's) and locked out of installing another one. Although you can install Firefox, Chrome, etc on iOS, it's still Safari's webkit engine underneath.
It's not as bad in some aspects, but the iOS ecosystem is essentially another platform. My current client has an app that's built on Ionic, and the sheer amount of bullshit I've had to deal with, specific to Mobile Safari, is insane.
In a lot of ways it's worse, Microsoft never banned the competition. It's utterly outrageous that Apple has been able to get away with such clear anti-competitive behaviour for this long.
There's only one reason Web Apps are not currently viable on mobile, and unless you're down in the trenches building these apps these issues are invisible.
