Sport betting can gives stable income if you can analyze lots of information and keep calm in stress situation. Of course with risk management, money management and strategy. But it stop to be classical gambling for fun and emotions that moment.
What you mentioned can be applied not only to sports betting but also to trading. Analyzing information in trading, as well as calmness and compliance with risk management, will lead to profit in the long term. However, it is worth noting that both sports betting and trading have moments that are impossible to predict. Whether it be a player's injury that will affect the outcome of the match and, therefore, your bet, or whether it be the manipulation of major players in the market.
May be i just don`t like it or don`t have enough time to become a specialist in one more profession - i don`t know, but my "bets" on the market are awful. In sport betting i calculated win rate i need, risks, some other things and i can say that have good(for me) strategy that works. I can`t make the same for trading. But again - i think that the problem is with my brains, not with trading.