The biggest issue with IE is it was HEAVILY integrated into windows. That in turn made it really slow to move. To get IE 6, you needed windows 2000, to get IE 7/8, you needed XP, to get 9+ you needed Vista.
That particularly became a problem because the time gap between XP and Vista was huge (and a lot of people skipped it and went to 7/8/10). In the meantime firefox and chrome came up and started innovating rapidly. Chrome started it with the evergreen model and FF quickly adopted that model.
That particularly became a problem because the time gap between XP and Vista was huge (and a lot of people skipped it and went to 7/8/10). In the meantime firefox and chrome came up and started innovating rapidly. Chrome started it with the evergreen model and FF quickly adopted that model.