Does the size of a Diaper bag matter

Do you really need to buy those big ol diaper bags? Or does any other size do the work? FTM . im having trouble looking for one and figuring out what size or what kind would help. And due date is in 2 more months.😭😓

Alot of pple say to get a big one cause of everything that the baby will need. So idk i wanted to know if you got a small diaper bag or backpack diaper bag. Or did any size helped you?