Assume you were replying to my comment so will reply!

So for the first part - this isn’t as simple as you suggest. First off, you need to be in the same country as most require KYC for your specific location (SSN or NI numbers). Second, few let you make your own peer-to-peer bets! Third, they tend to have significant fees or minimum deposits etc… regarding your second point layer 2 chains solve that issue and have done for the last year or more, fees are far far lower and sometimes even non-existent.

Also we probably don’t get to pick our own oracles! I don’t know of any site anywhere that does.

In comparison this is a fairly simple DApp to build.