Why do you think egghead arc is supposed to be long?
In a flashback, Oda revealed the Five Elders and their names and purpose...I don't see a 200-chapter side story like Dressrosa and wano...We entered the war directly, Oda shows that people like Lucci, who used to take 100 chapters to defeat him, now only takes 2 chapters....When the enemies arrive, we will see Luffy fighting them directly without boring 50 chapters for the new power-up....We have been reading Yonko stories for 10 years because Luffy didn't have the ability to defeat them. Now that Luffy has reached his highest level, the story will be shortened.
And in egghead, it seems that there will be a war between more than 2 crew.
About elbaf I used to want to make a thread that might be the best One Piece arc...But I changed my mind, Shanks is just having fun there with old friends and continues on his way..At best, Joy Boy is from here and we know something about him, and even if someone like bb gets there, it's not going to last more than 50 chapters.
And as I said, the story will not continue for more than 200 chapters, which is almost 6 years