This has always bugged me. Why does IE always lag behind in such CSS features? What kind of politics is this? Or is it that Microsoft does not have a big or smart enough browser team that can bring the IE/Edge features at par with Firefox/Chrome?
I've been so pissed off by this that I've started a micro-revolution by not caring if my blog renders well on IE/Edge. IE is pain in meeting compatibility with the CSP headers too. Hopefully more people start doing this so that people are forced to move to a better browser than IE.