Fiora was recently buffed in v9.8. Her W (Riposte) has its stun duration increased from 1.5s to 2 seconds. Her E (Bladework) had its mana cost reduced to 40 mana at all levels. Now, that's all good and all, but what isn't good is that her win rate literally didn't change at all. It's still a sub 49% wr at currently 48.8%. Objectively and imho she's still too weak. That's such a shame since I and many other players find her very fun and interesting to play, but other champions simply do her job better.
Fiora is mainly a split-pusher. She shoves waves with Tiamat and creates pressure on the map that way. The reason why she is a split-pusher is due to her great 1v1 potential so that she can keep creating pressure on the sidelines without giving up her life easily. This means that often 2 or more champs will have to come to her to kill her. However, at this point several problems occur. 1) She needs to win or go even in lane to be an actual split-pusher and 2) She relies a lot on her team to play defensively 3) Her team fighting potential is poor due to her telegraphed play-style (Vitals need to hit) hence the need for split-pushing and probably most importantly 4) Other champions in league simply does her job better. But, what champions you might ask?
Jax, Tryndamere and Yorick and probably more. All these champions have things in common. 1) Their laning phase is easier to execute. 2) They all scale greatly into mid/late game - they don't have to win lane. 3) Not only do they master the ability to split-push, but they all also have a kit that allows them to do better in team fights - they have options. Among those, Jax is probably the most similar champion to Fiora. For obvious reasons. But as I've said, Jax is also a very potent team fighter, especially with his AOE stun and general tankiness with his ultimate. Not only that, but currently Jax has an astonishingly high 52,59% win rate, which is top 3 among all top-laners. Meanwhile Yorick has a 52,57% wr (top 4) and Tryndamere is sitting at just over 50% wr. It's clear to see that all of Fioras direct split-pushing counterparts have vastly higher win rates. To put it simply, Fiora at 48.8% is completely underpowered.
And that's why I think that she should get another buff to (hopefully) hit 50% wr.
Fiora is currently way out of meta. Her win rate is at a measly 48.8%. Meanwhile, her direct split-pushing counterparts like Jax, Yorick and Tryndamere all have win rates at over 50% and pushing towards 53%. This is mainly due to them having an easier laning-phase which doesn't require them to get ahead because they scale so well and the fact that their team fighting ability is vastly superior and far simpler to that of Fiora. This means that there's really no reason to pick Fiora over the others if you want to be competitive and that is why she should get a (another) buff.