With automatic windows update there aren't really that many users left who are using IE version lower than 11. Browser stats metrics show that only 0.1% of all users are on IE < version 11.
What really matters are the stats for one's own users but who's stats say <IE11 is less than 0.1%? NetMarketShare reports of global desktop browsers for April [0] says:
IE11 13.62%
IE8 2.25%
IE9 1.32%
IE10 1.06%
Wikimedia global all-device browsing for April says:
IE11 4.8%
IE7 3.0%
IE9 0.43%
IE6 0.38%
IE8 0.25%
IE10 0.23%
IE4 0.22% (! I don't know what this is about, maybe an old mobile version?)
I wish they could somehow learn about Firefox, which is still supported on Windows XP. Then it would basically be just the people with old phones and 6-7+ year-old Macs that would require fallbacks.
That's a very skewed audience though, web developers aren't going to be using a super-outdated browser and Microsoft's browsers have been an unpopular choice of that audience for a very long time.
IE11 13.62% IE8 2.25% IE9 1.32% IE10 1.06%
Wikimedia global all-device browsing for April says:
IE11 4.8% IE7 3.0% IE9 0.43% IE6 0.38% IE8 0.25% IE10 0.23% IE4 0.22% (! I don't know what this is about, maybe an old mobile version?)
[0] https://www.netmarketshare.com/browser-market-share.aspx?qpr...
[1] https://analytics.wikimedia.org/dashboards/browsers/#all-sit...