More like story is 4 in JJK, 3 in shounens like Bleach or Naruto, 7-8 with DB (but it was 10 at times when it was not prolonged too badly), 9 with One piece, 10 with HxH or FMA. Be aware that beside Yuji other characters has either no background whatsoever, or has weak background like Gojo's backstory. But when it comes to fights and choreography maybe peak DB was that level, maybe Bleach sometimes, but JJK is the best fighting modern manga as of yet.
Basically JJK is more appealing Demon Slayer with nice main villain due to his presentation (voice actor mostly, he has done perfect work) but not the story (Sukuna is almost storyless. He kills because it's fun, we don't know nothing about him yet and this is almost the end of the manga).
If Gojo is just some image Sukuna's seeing prior to his death, it would be the best and most climatic option.
Again, except for boohoohoo flashbacks, I'm not talking about story since jjk is mostly fights.
Sorry if it wasn't clear, hard to translate my thoughts in English.
I love how Gege cut all the bs that polluted fight plots to keep the good stuff only.
It's more mature than all the shonens you mentioned but HxH.
That doesn't mean their bad shonen, just personal preference. I guess I've grown tired of the power of friendship and plot armor bs.
I'd rather read a story with a random MC with (almost) no background than a struggling guy that ends up being the son of the prophecy that gets all the/best powers.
Gon, Yuji, Eldrick bros above Luffy, Naruto and Ichigo all day, every day.
Even if their ascendants are powerhouse they don't get exponential, magical power up for free and their background are kinda boring.
I prefer when a author develop his MC in the present.
Luffy's crew is all about sad pasts but they all get tiny time screen now. What's point?
I love to see Yuji evolve. His background is non existent, but he's building a sick one right before our eyes.