&quot;As long as a measurable percentage of your users are still on these browsers, you&#x27;re missing out on money of you don&#x27;t support them.&quot;<p>This seems to be a common refrain here. It&#x27;s missing an important caveat: &quot;unless supporting those browsers costs more than the customers are worth&quot;. Supporting ancient IEs means things like: avoiding features that can&#x27;t be polyfilled, providing XP images for CI, debugging IE issues, etc. None of these happen for free.