I haven't used IE in forever - my guess is that you haven't either - which is why it starts going away in November
Launched in 1995, Internet Explorer was once the most popular way to reach the web worldwide, peaking in 2003 at 95% market share. But by 2010, usage was in free fall, as Apple took customers from Microsoft, and competing browsers like Firefox and Chrome sped past the slower Explorer. Meanwhile Microsoft shifted its business, focusing on cloud computing and selling devices like the Surface, new Xboxes, and really big earbuds. The death of Internet Explorer was a long time coming.
Via The Independent and a Microsoft blog post, Explorer will start phasing out on November 30th of 2020. At that time Microsoft Teams will be moving on, while the rest of the Microsoft 365 apps will continue running Explorer only until August 17th, 2021.
For more on the free-fall of IE - check this out