I grew up with it having to be a thing you do in front of others, but my cousin has done "thanks for the gifts!" broadly, but not opened them in front of everyone, and sent out thank you cards for her child the last couple of events, and tbh, I prefer that immensely. It's not interesting to sit around and watch someone open box after box after box, especially since they can't actually spend much time checking out a new gift or appreciate what the person was thinking of when there's a pressure to just get to the next present.
And also, I'm a lousy actor, so the times I've gotten weird gifts... I'm terrible at disguising my "wtf" reaction.