Interesting idea, but how sure are you that Bitcoin price is random? If someone is able to accurately predict the price all the time, he will be the winner all/most of the time.  Centralized Prediction Markets wouldn't be fair to such people... they will likely think they are cheating and have their funds seized then try to get  them arrested. So, such players will try to avoid the centralized exchanges for lottery, betting or predictions. This is why I like the idea of decentralized lottery or prediction markets.

Maybe more than one person should be able to win 1st, 2nd & 3rd places daily so it doesn't feel unfair and boring to people  who play constantly without winning.

The NFT part should be done on sidechains rather than mainchain though.