I almost built an application like this in the past using Bubble with a friend of mine. It is totally possible, but building a crypto betting app is really broad and would require way too many moving parts. What would be more helpful is if you had a specific bet type in mind. That way you can create a Smart Contract that represents that bet, use wallets for the money and identification management, and ultimately for the pay out.
You want to use the Bubble app for the contract interactions, but don’t do it for handling the actual betting logic.
I’m open to helping out further, let me know if that’s something you’re open to.