This is one reason I think projects like Servo are potentially very beneficial even well before they can render every legacy quirk you find on the open web. In

This is one reason I think projects like Servo are potentially very beneficial even well before they can render every legacy quirk you find on the open web. Instead of bringing a custom rendering engine to the web via WASM and canvas, it'd be better in so many ways to bring a subset of spec-compliant HTML rendering to embedded contexts. If your content renderer can run on Servo, and render the same in modern browsers, you can use HTML as the basis for cross-platform rendering. At least I would hope that would be possible by now so we don't have to write renderers for every platform anymore.