I've donated over $100 to Mozilla and even campaigned for them among various developer communities but unfortunately it seems like they either don't care about HDR for the Windows version or don't have a good way to hear all the demand behind it! @Ad...
And to everyone saying there isn't a lot of HDR content available or it's just limited to YouTube nature videos, they are completely ignoring all the movies and shows available through paid streaming providers like Amazon, Max, AppleTV, and Paramount...
Nearly 3 years later and still no HDR for Firefox Windows users. I've sadly switched to Edge (I know it's simply Chrome with it's own version of lipstick) and lament the incredibly poor lack of resources given to make HDR a reality for Windows users....