[michaelt]

All the major browsers came out when Windows XP had substantial market share.

So browser vendors couldn't rely on the platform to provide up-to-date SSL support. Or MP3 support. Or MPEG-4 support. Or PDF support. This established the norm that browsers would ship their own video support, their own SSL support, and so on.

And Google realised they like the power this gives them - if Google wants to replace HTTP with QUIC or introduce a new video DRM standard, or a new video codec like VP9 - they don't need the cooperation of anyone outside of Google.

If Chrome bundles DRM support (allowing it to play Netflix), and its own HTTP/2 stack for speed - are you going to release a browser that's slower and doesn't play Netflix? Doesn't sound like a recipe for big market share.