Honestly, it improves on a LOT of things better than it's predecessor. Better development with the main four (Ichi, Namba, Adachi, and Saeko) as well as some further developments with other characters (Seonhee being such a girfailure, girlboss and having a massive crush on Kiryu; Joonghi being a dorky stuck in a literal assassin's body, and Zhao running a restaurant to help support himself after his step down as leader), QoL improvements like being able to move in combat, and the insane amounts of detail and care that went into designing Hawaii.
That said, I will admit the main storyline for Kasuga's path is horrendously bad when in comparison to the last game. Be honest, did you care at all out Lani? I think that's what sums up my honest reaction to the main story. No caring enough. Like the bosses are a lot less memorable. Shirtless oneshot MF Tendo, Ishioda's excavator fight, curbstomping Aoki then crying about his eventual shift and realization about his familial importance to Ichiban - hell, even Kume was more memorable due to the fucking asshole he was to the main story. Now compare to Infinite Wealth, where Bryce and Ebina were HYPED up as either genius masterminds or "more monster than a man", when the most memorable aspect was their snoozefest of a monologue leading up to the fight. Don't even get me started on missed character potential. Roman, Wong Tou, even Dwight. It just sucks so much that the story takes such a huge nosedive in performance in the later half, especially with ending in the biggest cucking of character interaction between Haruto and Kiryu.
Y'know what didn't take a nosedive though? Fucking Yamai. Hooooly shit was he such a memorable and well written character. Man did they really knock it out of the park for not only did he grow as a person, but also played such a huge part in the story. Tomizawa was also such an amazingly written side character, and him and Yamai's history as well as interactions are what got me hooked to seeing more.
Anyways, enough rambling. It's a really good sequel, just wished they didn't fumble the latter half of the game so hard.