For luck based games, it could be true but for sports betting I think you can win more than your loss.
In sports betting yeah it's different you can analyze and have your strategy on what to bet. For some gamblers it's possible for them to have more wins but for me, it's difficult.
It's the same for me. I even start thinking again that sports betting is mostly luck based. I said again because in the past I thought it was no different from dice, where betting with 90% win chance you are more likely to win, but if you lose you lose 10 times more than you could potentially win. That's what I was thinking before starting actually do sports betting, and since I was lucky with that at first I changed my mind. It felt like I was really making good analysis and that that's why I was winning. Then luck turned away from me and I started losing more frequently ... In short, now I think that sports betting is a luck based game.
of course there is luck factor but not as much as dice games.