Listing counters, and one's that aren't even played often anymore to boot, does not invalidate a champion.
And using your same logic, oh look, talon was e'd. Deleted.
Oh look, Kayle was e'd. Deleted.
Gragas is probably the only one you mentioned that could survive ahri catching him with her e, but the problem you mentioned is that gragas has a dfg. If gragas has a dfg, then it's only logical to assume ahri has one too. Oh look, Gragas was e'd. Deleted.
There's a reason why she was still a viable pick, even after she was "nerfed". And it's because on paper, some champions can fight her pretty well. But in practice, it's a lot harder. Fizz is a counter to her, but it requires you being able to use your e for dodging her e and not wave clearing. If ahri just pushes it out using her q and then runs off to another lane, fizz's advantage is nullified. And if he runs after her, he then has to have hella fast reaction times or vision to avoid ahri just hiding in a bush for him to facecheck.