I’m with you, but even if curved is better, does it really matter for most people? Even if it did penetrate better, what are the chances of that alone changing the outcome of a shot ever in your life?
To me, it’s all marketing, and even if there was a difference, unless you are shooting 35# and short draw length for something like elk, you will never see any appreciable difference, it’s marketing gab.
I will put more thought into my 52# recurve broadhead and arrow setup than I will with my compound, but unless you are shooting low energy setups at big critters, I don’t think it’s a big deal