In case you have missed the announcement made about a year ago, Microsoft is killing Internet Explorer 10 and below next month. By killing they are no longer offering support. This means you will not receive any bug fixes or more importantly security updates.
Lack of security updates is a serious issue for individuals and businesses because security. Recently Chris Jackson shared a little simple data science showing just how vulnerable you are with these old browsers compared to IE 11 or Edge.
So if you or your business cares about security please upgrade to Internet Explorer 11 or Edge today. If you are afraid of your legacy business applications failing you should use Enterprise Mode (EMIE) to give them a safe refuge until you can upgrade those applications.