Doesn't Windows bundle an H.264 decoder? If Chrome made use of that, would they have to pay for their own licence?
These provided MFTs have to meet certain minimum requirements for certification by Microsoft, which amounts to "good enough." Results vary in practice and can be incredibly frustrating (especially encode). It's often better to use the underlying SDKs but that comes with a lot of hassle.
(I've been working on a video capture and sharing app inspired by Shadowplay.)
Windows 10 is also rolling out support for AV1, though not bundled.[4]
[1]: https://docs.microsoft.com/en-us/windows/win32/medfound/h-26...
[2]: https://docs.microsoft.com/en-us/windows/win32/medfound/abou...
[3]: https://chromium.googlesource.com/chromium/src/+/master/medi...
[4]: https://www.microsoft.com/en-us/p/av1-video-extension/9mvzqv...
Why do they need to pay for their own licence then?
But most Browsers tends to implement their own for all sort of reasons.