I highly, highly doubt that the share of people who consistently stay in category 1 year-over-year is more than a couple percentage points. Lots of people put $50 in to try the whole thing out, lose, then never return. Extremely few people will then return in 2025 and be like "lets do that again".

I cannot for the life of me understand why these apps can't make money off the pros, and instead need to ban them. Ignoring all the dumb promotions these apps do: Sports betting is zero sum, you're betting against the other players, not the house. The odds are set by who you're betting against. Literally, how does it not work out that the profit is just the money from the losers minus the house 30%-or-whatever cut? Is "pros" in this context people who also frequently abuse the (oftentimes wild) promotions these apps run?

But, if it did work like that, the problem is even more apparent: these apps are at best a direct wealth transfer from addicts and idiots to corporations and pros. Wait, I just described the stock market, we're talking about sports betting :)