While competitors chased a trillion-dollar live shopping market, @Whatnot noticed its own customers turning livestreams into storefronts. Co-founder and CEO Grant LaFontaine on what users really care about: "They care about whether they're gonna enjoy the thing, whether it provides value." "There's this counterintuitive thing, which is if you try and build a market, it oftentimes distracts from: are you building a really great user experience?" "We were building our Funko Pop marketplace,…