The Battle Pass
Fortnite didn't invent microtransactions, subscriptions, or earning rewards for playing multiplayer matches. But the way Fortnite packaged its Battle Pass structure allowed it to generate revenue without making the anti-microtransaction sects of the gamer collective angry. This allowed Fortnite to thrive and also spilled into other games like Rocket League and PUBG, which struggled to keep making money otherwise without ticking anybody off. We could end up seeing this idea come to plenty of other games as well, as it seems to be hitting that elusive revenue-generating sweet spot.