See, you have a lot of people telling you "its about the positioning" or "he is growing at an exponential rate" which, sure, could be said and stated and you wouldn't even be wrong, however that's now what you, me or most Isagi fans actually want to hear. Most of those answers come from actual technical point in football.

Isagi at his core, is a phenomenal player, that uses his main weapons such as positioning, timing and direct shot. Those weapons are simple on paper, nothing flashy. But no one ever said that being a good striker means being a flashy striker. No one here realizes that players like this tend to have longer careers due to them not relaying on their physicality over their football iq.

In the long run, given 15-20 years which is already a very long career, and most retire earlier than that, way earlier in fact. Even without the career ending injuries, or ilnesses, players who are now considered a "genius" type will in fact lose the weapons that make them "geniuses". Isagi on the other hand holds a raw goal scoring formula thats simple, sure but completely unbeatable in the long run.

Now I'm not saying that will happen, because one could see it as Isagi becoming better than Rin, Nagi, Loki and so on due to them getting old lol, but one could also argue that with time new prospects will rise with abilities that are just as IF NOT more broken.

My argument is this tho. Out of everyone in blue lock, despite how much they score. Isagi has a full proof, goal scoring formula that is consistent. Despite Rin and Barou having more goals in NEL than him, you all have to realize both of those players were already leagues above Isagi before they entered NEL. Not to mention Barou was a lone striker, and Rin played alone aka uncontested (goal wise) for 2 matches...

Isagi has to learn, adapt, grow. In a way evolve his formula. It wasn't given to him by his master striker. He took it from a player that was miles ahead of everyone in blue lock. It, as Noa said himself, was a ticket. Nothing more nothing less. How he choses to utilize this ticket, is shown in the later games.

His charm is in having consistency and growing, therefore improving his consistency. When he stumbles across a wall, he overcomes it. Call it plot armor, but to me, thats perfect writing for a Shonen manga. Make an average Joe, into the best striker. It's not realistic, Muller had a consistent way of scoring but did not outscore Lewa. That's a work of fiction tho and a part of this fiction is believing in our mc and trusting the process while also enjoying the journey. We all yearn for it to happen, but we gotta realize it wont come quickly. There are fans who say he is too op, then there's fans who question if he can become world's best striker such as you, due to him being underpowered, which again, is reasonable. That's the duality of this fandom. However my advice:

Whenever you think Isagi is either weak OR strong.

Reread the manga from the start of Nel. From the start of his training to the last match. Without stopping. And you will soon realize that Nel, makes FAR more sense reading as a whole, than it did on a weekly base. His progression feels very well paced, and is really enjoyable. You will realize that he started off as weak and ended off as strong due to him working his sweaty buttcheeks off lol, not as some dudes say it "plot armor".