What makes you think they will?
Supernovas are the same as when they popped-up.
Most of the crew have gotten little outside of their timeskip wardrobe change. With most of their "growth" being duct taped on to them (e.g. zoro's new sword, sanji's raid suit, zeus with nami).
Characters in this manga either stay stagnant or have some ill-conceived glow up.
Heck, you could say Oda doesn't even grow his characters, he just retcons them.
"What is character development?" - Oda
"It just works." - Oda
Bro what are you talking about? Like, walk me through this, because I do consider myself a more casual OP fan, but Oda did pretty well developing the SH this second half as far as combat and that paying off.
Usopp: Spend the TS training on an island, comes back with new weapon and Oda confirmation of being as strong as pre-TS Zoro. Over the last few arcs he has, awakened Haki, earned a new nickname and bounty (sogeking still hasn’t been confirmed to populace right?), helped earn a grand fleet for the crew (which honestly he makes the most since ordering around and still being able to fill his , and spent time training his invention skills and other abilities on Wano while waiting and spying.
Chopper: special doctor training, which has paid off each arc of the new world. As well as having the effect of allowing him to manipulate his DF even better and upgrade his rumble tech, which was pushed further by his exposure to ceaser, but came to fruition during his time in Wano learning and experimenting to prepare for battle.
Robin: spent TS becoming a spy for the resistance, which directly tied into her own desire to learn more and get info regardless of barriers. Which also included specialized combat training, which she has continued to practice. As well as learning more soy skills while in Wano, and adding official seduction techniques to her repitior (though opinions may vary over this)
Brooke: Spent time performing which seems odd, but led to experimenting with his DF and gaining a new dimension to his DF powers. Which culminated in allowing him to be proven true Kryptonite for an entire Yonkou’s special ability. An is continuing to polish both those skills and his swordsmanship in Wano.
Nami: spent the break getting an even better understanding of her role and new weather tech. Which she immediately had incorporated into her weapon. She Followed that up by earning the loyalty of one of BM main weapons which she eventually gained full control over, giving her the largest combat upgrade yet. She also spent all her time in Wano training as a ninja.
Sanji: he get allot of flak, but my man leaned flight over the break and Haki as well. Even became a specialist. Then he got the raid suit last arc, which is apparently amping him long term. He also got the chance to take his cooking skills up a few notches in this arc and the last one. Continuing the trend of the SH growing in ways that support their actual personal goals.
Franky: Spent the TS pillaging vegapunk’s inventions. He was able to upgrade himself, and had been working to incorporate it into his weapons. Allowing him to have some of the better fights in this part of the story. An he hasn’t even awakened a Haki yet (I’m calling armament. Preferably while holding off all these Kaido subordinates after beating a TR as a perfect scenario to bloom in.)
Jinbei: joined, and still revealing new skills and power this arc. Even if the Haki was already expected. Nice to finally officially have my man on the ship. Please stay on it. No going to gather the fleet or nothing.
Zoro: trained with Mihawk, then learned to cut fire (opening the path to cutting other elements), new super Haki sword, spend whole time in Wano, picking duels and causing problems and polishing his sword skills further.
That’s not even including Yamato as a fun possible addition. I mean, I get complaining about where you want the SH to be, but to ignore what has been done doesn’t seem entirely fair. A much more fair critique might be Oda hasn’t put the expected or maybe rather desired time in letting all of them show off these new skills and have sufficient challenges. I was also hoping for a bit more. I think Usopp and Nami should have beat those siblings without major interference just to infer how far they’ve really come. Since we know they will be expected to fight BB crew and survive the major war with the marines.