Ezreal's probably the healthiest marksmen

He's one of the only marksman that doesn't rely on crit or lethality.

He can survive early with his mobility and do stuff because of his q range. He spikes mid-game but doesn't fall off. He falls off in comparison, He's one of the only ADs that feels like they're DPSing over time and not melting people (bork and attack speed buffs). He also can't really ignore tanks because most of his damage (q) is a skillshot. His build doesn't rely on crit so you have OPTIONS (like you can build maw second and not make urself useless). You have multiple possible builds which each have trade-offs.

The only time ezreal feels super worthless is when the enemy team gets baron.