Yeah, but sports betting is a bit different from other type of gambling games where luck is the paramount thing, I agree that there are no guarantees of anything and there is always that high chances that in the long term, the gambler may have lost more than they actually have won, but on the other hand, we can't completely rule out the possibility that the gambler may gain even much more as well depending on how good he or she is with predicting accurately and also the type of luck on their side.
It Is possible for a bettor to remain in profit even after having been betting for several years, it is very possible but just that the chances are slim, but the chances being slim does not also mean impossibility, sports betting is not like casino or slot games where players are completely dependent on luck alone.
Ofcourse, there is always a possibility of that. I never said it's impossible to win in the long term in sports betting.
Although I mentioned losses are definitely going to strike us hard, we all know how luck can change everything if it's on our side.
As you said, it is possible yet the chances are slim otherwise everyone would be leaving their jobs and doing sports betting.

I have been active in sportsbetting for about 15 years and read many forums/blogs of people claiming they always make a profit on sports betting but in reality very few can make a positive ROI year after year. The only person I knew that was successful was a guy that only placed bets on cycling competitions. It could be that OP is really that good at sports betting but allow me to have some doubts.