Even though many people that bet on sportbet are not that knowledgeable, there are people that are still making huge profits from betting. There are people that had gain the knowledge and pattern of betting and having a consistent winning and they don't waste time making money from sport bet. Sport bet is very easy to make profits but some persons had used greed to scatter there possibility of making winnings which is one of the problems of gamblers.
I doubt it. People making a living out of sports betting are like unicorns, everyone has heard about them but no one has seen them in real life.
The only way to make consistent profits would be arbitrage betting. The problems with that are: 1) you have limited opportunities; 2) sooner or later, it'll get you banned from betting platforms.
Other than that I see no realistic option for regular profit. You making consistent wins would require bookies to keep miscalculating odds in your favour, which is unlikely to happen (on a regular basis).
If someone is able to successfully use arbitrage continuously, he can win. The person can get caught if having multiple accounts in the same betting site, but you can do the arbitrage betting using different sites and do not violate rules at all.
Another way to make money from gambling is to be visiting new reputable sites with first time deposit bonus. Some gamblers visit those sites because they want to use the bonus to make more money. But this can be dangerous, news sites needs to be investigated to know if it is fake or not. You can also register on many old sites which have first time deposit bonus.
But to bet and win without this two things above, no one can win the gambling site.