Pick him against champs with weak early games, don't spend 4k for ~40 ad, win game. Ezreal has his place, but it's as a counter-pick to strong lategame champions, not *as* a strong lategame champion. Look up some of the good Ezreal guides out there - all of them (for bot) build close to a standard AD carry build, and none of them rush Trinity Force before other AD items. When Ezreal is built this way, he's quite scary in the early game and is capable of either forcing that 20-25m game, or winning around 30m because the enemy AD wasn't allowed to snowball early.