I feel like he had a better head on his shoulder preTS - that conversation with Vivi in Arabasta comes to mind. PostTS, he doesn't have many displays of maturity and he's become more of a caricature of what someone would think Luffy is. However, I really liked the way he was made to handle Pedro's death. Him being the mature one in that situation was a breath of fresh air, and I wish there was more of that in Wano rather than just repeating the same phrases and stuff like "I have infinite chances".