Ashe

Ashe is very squishy which makes her an easy target for you if you get fed, but she also has a great slow with her passive that makes her very hard to escape from. Though she doesn't have the best early-game potential, her first level is very strong as her passive gives her enormous dueling potential. Don't use your E if you don't have to as otherwise she can just run you down and win an easy trade. She also has a very good auto-attack range that you should be aware of. You have to remember that her ult has infinite range just like yours and its stun is longer based on traveling time so if she uses it from her base it probably gives you the scariest 3 seconds of your life as the enemies have 3 seconds to kill you while you can't do anything so it is acceptable to use Flash to dodge it.

Jhin

Jhin's Roots are Traps are a rough matchup for Ezreal due to the CC. Ezreal needs to have his E available to damage enemy champions. If he has to use it to escape any CC it leaves him vulnerable and inhibits his full burst potential.

Seraphine

Seraphine has lots of range and wave clear. If she walks up and clears the wave and goes back under her tower it makes it hard for you to farm because of Ezreal's lack of wave clear. Her large AoE attacks effectively zone Ezreal out of fights and the easy-to-land slows, roots, and charms make it easy to lock down Ezreal.

Yasuo

Blocks all ranged attacks/abilities. If Yasuo stands inside his wind wall it stops Ezreal's entire kit, rendering him useless in skirmishes and team fights.

Ziggs

Ziggs is one of the worst champs to play Ezreal into, he can burst you before you can burst him. The long range provided by his spammable Q makes it almost impossible to reach.

Vayne

Nilah

Nilah is the only ADC that is a melee champion instead of a ranged champion (sorry Yasuo you are not an ADC, better stay mid) which makes it a lot harder for her to get kills against other ADCs early. Don't get me wrong, Nilah is one of the strongest ADCs in the game with her great kit and auto-attack damage. Her passive also pretty much makes sure that she will be a level ahead of you at all points of the game. She can also ignore all the auto attacks from you and can get the same protection to her adc. You can pretty much poke her freely early but she will mostly stay behind minions so you can't poke her. She also has two dashes that give her a really good mobility that makes it possible for her to even run you down if you don't have Flash.

Lucian

Lucian has one of the best early damages among all the adc's on the rift. His combo damage is pretty much unmatched as with his passive it is possible for him to nearly oneshot you at level 3. If he dashes to you, just E away. Farm safely early, he will fall off late compared to you

Samira

Samira isn't the best early-game champion as most of her damage comes with her ult at level 6. Before that she shouldn't be too much of a threat to you. Remember that she can block your abilities with her W so don't count on your ult if she has it up. Samira usually plays with cc supports and they aren't usually anything serious for Ezreal as long as you have your E to rely on.

Tristana

Tristana has really good damage and a long-range jump so you don't have anything to do but to farm from far and wait for a gank. If she jumps towards you, E away immediately, or you might find yourself dead in a second.

Kalista

Kalista is one of the hardest ADCs to play in the whole game which makes this matchup very elo dependent. In low Elo Kalista players don't know how to play the champion but in high Elo, the players can use the mechanics of the champion a lot better which makes this a harder matchup. Overall Kalista can't do too much to you if she doesn't get close to you as she can't get stacks to her passive. She can dash on every auto attack so if she gets close to you it is really hard to get rid of her. Additionally, a good Kalista player can dodge your abilities with her dashes which lowers your damage input a lot. I don't recommend you to go to a close-range fight with her as it won't end up well. Only take fights if you have a really good fight setup from your jungler/support. Farm and poke her with your Q and W. Always save your E for those moments when she can get inside auto-attack range.

Draven

Draven is the absolute king of the laning phase, his bonus auto attack damage from his Q combined with the movement speed boost and the cc is unmatched among all the adcs on the rift. Wait for laning phase to end, don't play aggressively, don't fight, he has a really good snowballing potential due to his passive. I strongly recommend not picking Ezreal into Draven.

Pyke

His hook doesn't have a long cooldown so you can't count on your E to save you from him. He also has a great sustain with his passive and a great mobility that makes him impossible for you to kill. It is really hard to play safe against a good Pyke player as they will always find a way to land their cc on you.

Kog'Maw

Kog'Maw is a champion that can deal surprisingly much damage in the early for a late-game champion. Try to bully him early or you might find yourself in a really bad situation with a Kog'Maw that has got fed from just farming peacefully. You can E out of his E to prevent him from dealing damage to you.

Twitch

Twitch is a great late-game adc with tons of damage, but he isn't too good early which means that you should poke him as much as you can and stomp him hard in lane so he can't carry later on.

Jinx

Jinx's kit doesn't provide too much counter to you as you can E over her traps/ult and her range isn't even near enough to get you down. Don't recall under turret if you are low health as Jinx could easily kill you with her ult as it deals bonus damage based on traveled distance. Her damage in a close-range fight is really good due to her auto attack buffs of her Q. It is better to stay safe early as a fed Jinx can be a real problem in mid/late game.