The goal of curation is to identify the most valued needles hidden in the haystacks in the most timely manner. At that level, users can't yet tell us what they like, because most users haven't even seen the content yet.
It has to be a skill game otherwise you are asserting that curation has no value added. (If there is value, then people will differ in their ability to deliver that value and the only way to assess those differences and maximize the value delivered in exchange for the rewards paid is via competition.)
I don't believe that there is no value, and neither does the system design (nor does the obvious observation of the amount of money spent by various companies on people and algorithms to perform curation). So lets dismiss that possibility.
People or bots (which are always controlled by people, for the time being at least) that are able to identify the most valued content the earliest are the most rewarded. That is inherently competitive and must be a skill game to function. It is also very, very close to how the current system is designed.
Not everyone will decide to compete in that game (just as not everyone will post, or comment, or mine or be a witness or develop software), some will just vote for what they like, which is perfectly fine. Others will be gamers or algorithm designers or talent scouts or promoters. There is room for all these roles and more within the broad scope of "curation".
And on top of all that, I don't see anything wrong with there being a skill game component simply for the purpose of playing the game, if that attracts interest from people who want to play (as seems to be happening to some extent already). Why not?