I definitely get that your anxious to jump into war but the fans have a high expectation of Wano and it cannot be reached with a version as mundane as go to war, and the end. Story is everything in One Piece, this flashback,, the chills....the tears..the reveals we will get from this... these moments are usually what end up in most fans Top moments in OP, it's what Oda does best, telling a story.
Wano is the most mysterious island connected to the void century that we've sailed to period. Oden, Lady Toki, Whitebeard, Roger.
There is just simply too much lore, story, reveals, and epic shit from this flashback and Wano overarching story as a whole, to skip all of it and go to a war and we leave Wano, it would just be too damn underwhelming.
No rush, let's enjoy this flashback and get the most out of One Piece lore before this epic tale is over. The war will still be there waiting and will be that much greater for it.