I like the idea, but imo we need to treat inbound email differently than a task list. I think inbound email should have a rich set of filtering/grouping/bulk archiving tools to sift through the junk quickly, and then a seamless way of converting the actionable items into to-dos. I don't think Gmail handles either of these parts very well.

When you think about it, gmail is just one input into your list of things to do for the day - so you could imagine other integrations like Github PRs that end up there. Anyway, I'm glad people are still working on this problem, I consider it very much unsolved.