I don't want diversity. I want every website to work in every browser I use on whatever device I use it. Chromium the rendering engine is open source and isn't developed by few in one organisation. Yes its the engine behind Chrome, but then it is also the engine behind other browsers. I'm happy for there to be diversity in browsers, pick which ever one you think has the most usable UI (everyone has a different opinion). People shouldn't really care what rendering engine it uses, as long as pages look the same for everyone everywhere, which really is the goal.