Security:
Without critical browser security updates, your PC may become vulnerable to harmful viruses, spyware, and other malicious software which can steal or damage your business data and information.
Lack of Independent Software Vendor (ISV) Support:
Many software vendors no longer support older versions of Internet Explorer. For example, Office 365 takes advantage of modern web standards and runs best with the latest browser.
Compliance:
Businesses that are governed by regulatory obligations such as HIPAA should conduct due diligence to assess whether they are still able to satisfy compliance requirements using unsupported software.
But, what does “end of support” means?
End of support means there will be no more security updates, non-security updates, free or paid assisted support options, or online technical content updates.
Source: www.microsoft.com