I think that we can't take the it as a competition. uni and pancake operated on the different chain and that makes me wanna say if it's not reliable to make a comparison between the platform that built in the different chain.
UNI for ethereum users and pancake for BSC users.
You are absolutely correct, it's a lame comparison. But it's not entirely wrong when someone makes such a comparison, because when dealing with Uni, you will pay a fee that is dozens or even hundreds of times higher when dealing with Pancake. Uni is sure to grow, Pancake too, it's important that our judgment on which one will go further.