One thing not mentioned here, is how this also affects those not gambling. People act as if the only problem is how it exploits gambling addicts.
But it fundamentally changes sports. Both the amount of money in them, which comes with their own problems (see ManCity's judgement today). But also how players are affected. I know a soccer player in lower divisions getting death threats because someone in another country was gambling on their match. People try to bribe what's basically amateurs etc.