What if someone made a website where you pay $1 to enter every week in a competiton of XPs the winner in XPs gets $100.
in each week's competition programmers world wide compete for xps and the xps are obtained by answering questions and challenging people just like in sololearn then the top three programmers at the end of every week get prizes. do you like the idea.
Adding to Martin, such method tend to lure people into developing cheat techniques, and/or "support teams" to help the winner to win.
The only way your going to make this happen is if you start it, I'd suggest teaming up with sololearn and offer xp as rewards and gain money through ads instead you never know they might like the idea.