Honestly, Hidden Inventory Arc is the most well-written arc of JJK. It's completely self contained- and beautifully done. Gege doesn't manage to do better than this for the rest of the entire manga. In terms of the heart, I'd say this is it. This is the heart of the story. It captures the toll of the Curse Cycle on young minds and really hits home the cruelty of the world of Jujutsu Kaisen. But in way that makes us empathize with every character. That's what I love about this arc- it's not got any generic villain caricatures (like Sukuna) nor does it have sadist cursedspirits (like Mahito) making life difficult for our MCs. It's just got humans, broken down and beaten, by an unforgiving system- and their desperation which drives them to either overcome their limitations or give into madness. Premature Death of innocents and innocence.

No matter how egregious the ending of JJK ended up being, this arc will always to be timeless and precious.