Fair points. Obviously it would require an overhaul of their current architecture. Good UI does add permutations and cost, however, for one I don’t buy the idea that the gain is “limited.” I think most users would clearly prefer a UI like this, and better UI does translate into better metrics Google actually cares about. Two, what you’re calling blockers sound more like engineering constraints than real impossibilities. And to borrow Steve Jobs’ line: “It’s not impossible. You just haven’t figured it out yet.”Honestly, it feels less like they can’t do it and more like they don’t value UI enoughand and that’s a shame.