Unless you're talking about the playtest, DnD you double all the damage dice, not just the base weapon dice. Sneak attack, smites, anything that's not locked away behind a separate saving throw (like poisons) or just a flat damage boost (like +5 to STR) all gets doubled.
PF2e is great though, would love if one of my games switched over some time.
I mean, think about how many farmers have turned into level 20 John Fighterman. She's got an army of level 20 souls who can all attack 8 times in the first couple rounds each.