Shouldn't we buff talon?

Splitting my replies into paragraphs.

Your entire argument seems to be "Oh, Talon has some strengths over Zed, you even said so! Abuse them and he's not inferior!" and that just isn't true. They fill the same niche now, and Zed does it better.

Every assassin is situational, the point is that Talon is even more situational. He has always been a niche pick, and his niche has been reduced even further.

The reason is because while Talon can abuse HIS strengths, so can Zed. If we're discussing skill making the difference, Talon loses out again, because his skill ceiling is lower than Zeds, going back to Zed's superior outplay potential. That is why simply playing to Talon's strengths is insufficient. You could simply play to Zed's strengths and do better with far less weaknesses.

As for your rhetoric following that argument, it is a false equivalency. Darius and Maokai don't fill the same role, and one is an early game bully. Your argument then seems to turn into "Yeah Talon isn't a master of all, but he performs one role better and if you abuse that it can make him coexist with Zed." That used to be true. Talon used to be a superior anti-mage, and therefore he successfully coexisted with Zed because he did do one thing strictly better that is meaningful enough to warrant his pick. However, due to his nerfs, he fills the exact same role as Zed.

A better comparison would be Rengar and Nocturne. Both are AD pick assassins, capable of going for a high damage or bruiser builds, both jungle, both farm well and both have CC and defense mechanisms to stick to their respective targets. They are, therefore, comparable. However, why pick one over the other? Rengar has his reveal potion of his ultimate, faster hard CC, and his Ferocity regeneration helps his staying power in a fight. Nocturne, on the other hand, is even stickier with his spellshield and more accessible movespeed boost, has a much more instant ultimate and denies vision to the enemy rather than grants it for himself. Depending on what your composition and you as a player prefer, both can be justifiably picked. This, however, still isn't the same as Talon and Zed, leading to my final argument.

THE END POINT IS THIS: Advantages over other champions are not a simple matter. Some are simply more meaningful than others, some depend on a certain team composition, some fare better against certain champions, some are better in certain situations and so fourth. However, Talon and Zed are so comparable in both strengths and weaknesses that they are directly comparable. Time had it, this wasn't the case. Talon had a legitimate reason to be chosen over Zed, and that was his use as a counterpick. Now? They perform the same role, and Zed does it better.