During that era was a peak of browser innovation. IE5 and IE6 contributed a lot of things to web standards. They contributed a bunch of things that web standards eventually rejected too, but that was the risk of innovation at the time.
It was the period between IE6's last feature update and IE7's first release where Microsoft declared the browser wars "finished" and disbanded the IE team entirely that was the Darkest Age. So about 2001-2006 were the darkest few years.
It certainly had repercussions until around 2010, but the worst "sabotages" were done and gone by then. "Legacy" problems.
I would say the darkest era was after IE7 was released: 2006-2010.
You could see all the new features, you could use them, you could design your site around them. But so many people refused to upgrade, so as a web developer you were forced to do stupid things to make IE6 work.
And it's not like IE7 was that much better. You needed to put effort into making that work too. At least Chrome and Firefox would usually both do the same thing.
During that era was a peak of browser innovation. IE5 and IE6 contributed a lot of things to web standards. They contributed a bunch of things that web standards eventually rejected too, but that was the risk of innovation at the time.
It was the period between IE6's last feature update and IE7's first release where Microsoft declared the browser wars "finished" and disbanded the IE team entirely that was the Darkest Age. So about 2001-2006 were the darkest few years.
It certainly had repercussions until around 2010, but the worst "sabotages" were done and gone by then. "Legacy" problems.