Fiora's early game isn't actually as amazing as you all make seem, and neither is her lategame

First, did you know you could reset her Vitals? They always appear in a different place when you do. Even if this doesn't stop her from proccing them, it means she needed to go behind you to do so, and thus in your minions, and thus now you can fuck her over. And if you complain about needing to do that, you might as well complain about having to stand behind minions in order to dodge Blitz Q's, because it's entirely your fault if you let her get a free Q on a Vital. Sure it might make you miss some cs, but so does the threat of Blitz Q or Thresh hook. It won't kill you or lose you the lane.

Second, Fiora's lategame isn't godly either. Many duelist bruisers, skirmishers, and assassins, can actually go head to head with Fiora as long as she isn't fed. It's just the teamfighting bruisers, tanks, and juggernauts who she fucks over almost automatically. That being said, there's always the option of forcing Fiora into a teamfight (bring the fight to her lane), in which she doesn't do very well. "But she has an attack speed slow that fucks ADC's and possibly a stun, and an AoE teamwide heal which are all great for teamfighting!" Perhaps, but you know what she doesn't have? The ability to gapclose onto a high ranged mage or ADC. Lower ranged ADC's are in more danger, but should have a front line to keep Fiora off them. And Fiora's low ranged - if she just focuses the tanks, you can still hit her with ADC and mage damage. And if you think she can just peel off divers with damage, you might as well argue that Pantheon doesn't fall off, because he could do that better.

Third, you don't even need to force her into a teamfight. Take someone with which a 1v1 is a skill matchup, or even slightly against them, and stick them in the same lane as Fiora. Make sure they have waveclear, and either sustain, or the ability to avoid Fiora's Q poke. Then stop Fiora from doing shit. This isn't an 'auto win' strategy, and it doesn't even help you win all that much at all, unlike how bringing Fiora into a teamfight tilts it into your favor (it's basically a 5v4.5), but it means Fiora is not doing anything. The game will be decided by the 4v4 on the other side of the map, and if they win, Fiora had nothing to do with it.

TL,DR: Fiora's early game isn't that great, but more importantly her lategame isn't either because there are actually quite a few champions who can duel her, and because you can stall her split or bring her into a teamfight where she does badly.