From a "Do Nothing Bread" recipe:
Bulk ferment for 24 hours giving it a S+F inside the bowl at the 12 hour mark.
After 24 hours turn the dough out on a well floured worktop and with well floured hands and scraper form a rough boule or whatever shape you want.
Final proof in banneton for 1 hour.
What changed inside the dough during the shaping that requires a separate final proofing? In other words, why not bulk ferment for 25 hours, shape, and bake? [I understand that "24 hours" is a figure of convenience that means "roughly 24 hours."]
[If there's a better sub-forum for questions like this, please let me know!]
I am not close to being an expert like others here but I believe the final proof allows the dough to relax and gain volume after you shape it.
I am sure others can give a much deeper explanation
Dave
shaping the dough allows you to get tension on the outside of the dough so that your bake will get volume/oven spring. letting the dough to rest after shaping allows the dough to establish a firm "base", if you will.
when the dough is shaped, the entire surface benefits and will maintain this tension. if baked right away, it will bake more with a shperical shape. if shaping into a batard, it'll bake more like a football.