The main thing is how there is no true Counter. Lets compare Neon to the duelist she is seen replacing. Jett, who has an analogous ability to the slide. A dash
Neon, can shoot while moving(the slide), Jett, has to complete moving first then shoot. She cant shoot mid dash
If you notice. Jett and Neon can be both killed mid movement. But neon, she can fight back, jett cant. I imagine if we could have jett fight back the same way jett would've been called OP.
Sure counters like slows and stuns exist. But they're conditional. If you land it only does it work. It is not a true player counter.
What i mean by this is, lets say im playing deadlock, and i encounter a cypher trip, i can shoot it. If i encounter a vyse wall i can bait it by jump peeking or getting my team to peek in all at once. If i encounter a yoru tp i can break it or hold it as bait, if i get a flash i can turn it, if i have a molly i can move away. But Neon, if i encounter a sliding Neon, she can shoot me like 7-8 times out of 10, but i, have to track her moving at Mach 3(especially with the judge, cuz then they're so close its harder to track cuz its more distance they cover on your screen), to shoot her.
Sure You can counter it with teammates, but thats conditional. Not a true counter. And especially against a good neon duo(best example is dambi francis in santiago) , you find it impossible to fight cuz both of them can kill you and you need to channel prime demon 1 aspas and tenZ or what ever just to survive.