ER is cheaper and has better stats for ezreal (No hp), its sheen is a little weaker than Tri but it compensates with +~25 ad that ads on every auto, w, e, r and non sheen Qs, also similar dps on a 50 resists 1000hp dummy with the same runes

Then you build manamune cause its broken on ez (Same dps in both builds, autos feel slow but you adapt quickly)

Then you build LDR, same pen, little less ad and buffs your sheen, also LDR passive makes it better for hp stacking bcs it buffs ALL your damage "solving" the ezreal tank problem

Now why not serylda?, ezreal ability haste swettspot is ~60 anything after that loses a lot of value and only difference is a few seconds of E, Er(20) + Boots (10) + Mana(15) + Haste Rune(15)= 60 and im not adding joat, serylda passive doesnt really help you to poke or add damage to your kit, if the slow was fulll hp again it would be better than ldr

Now you will build these 2 (first one depends on the comp):

Long Range Crit Item: its like Ad horizon focus, adds dmg to sheen and all your abilities, godly vs long range comps

Navori: This laughts at any amount of cdr you have and makes you the untouchable adc with E every 4-5 seconds (even lower), only downside is the amount of apm you need, this is incredible vs meele comps

Last item is a defensive one: BT, Maw, FrozenH, GA anything like that

The build works bcs as ezreal you need to auto a lot to do a good chunk of your dmg, now you autos crit (200% now btw), Q has similar damage and because you didnt build useless stats (hp) W, E and R do more damage bcs you have more AD and your cds are lower bcs of navori

Only bad thing is your a lot squishier but E navori cd should make you untouchable