That's what I thought, too. But according to Reddit?
You "win" D&D every time you score a critical hit, which thanks to your Improved Critical feature will happen 10% of the time, and when it does it will trigger your Great Weapon Master feat and allows you to make a third attack with your two-handed weapon, and since you are a Halfling with the Lucky feat, you can crit-fish for another 19 or 20...
...or you "win" by casting Longstrider and Spike Growth, then Wildshape into an air elemental and grapple your foe and dragging them along the spikes for guaranteed damage (even if the foe is Legendary) and if you use Cunning Action to Dash as a Bonus Action, you can double that damage...and if you can get someone to Haste you, and someone else to Enlarge you, and...
...or you "win" D&D by taking a one-level dip of Druid to get the Goodberry spell, then using your Life Domain power to quadruple the healing potential of each berry, allowing you to heal 40hp of damage with a single 1st level spell slot...
...or you "win" every time you successfully exploit the Warlock's Moon Invocation and the Divine Soul Sorcerer's Greater Restoration spell to get unlimited Sorcerer spell slots...
...etc., etc.