Just try to run a B2B SaaS without supporting IE11. You will lose out on a ton of large-but-slow-moving customers. Like banks, insurance companies, etc. who all seem to have critical internal systems that only work on IE11 in compatibility mode.
This is why our company is still supporting IE11, and will be for some time to come.
Personally, I'm hoping the app my team builds will be able to finally drop IE11 support once the new Chromium-based Edge app becomes available on Windows 7 and 8.
Just try to run a B2B SaaS without supporting IE11. You will lose out on a ton of large-but-slow-moving customers. Like banks, insurance companies, etc. who all seem to have critical internal systems that only work on IE11 in compatibility mode.