I've seen that these two smart contracts are often used, and the ETH is widely used more often than WAVES. What is the difference between the two platforms?
If you really want an answer to this question you should do your own research. Asking it here will just get you the opinions of people who don't really know what they are talking about as I can see just by looking at the first page of answers. Don't be lazy, do your own research because that is what will give you the advantage over the rest of the players in the market.