Regarding the gambling strategy by never doing gambling, it is a poor idea. Just stop dreaming if you have no intention to face hard work. The idea should be more selective and smarter to gamble. You may also need to learn from others or evaluate your current strategy.
There is no amount of hard work that could create a winning gambling strategy. It simply doesn't exist. The analogy presented by the other poster doesn't fit here. Quiting a job because you don't like your boss is a good thing. You can find another better job.
Gambling is entertainment for the gamblers. For the betting institutions it is business and they wouldn't be in this business if it wasn't profitable. The only way it can be profitable is if enough gamblers lose their money. It is that simple. It can be profitable for gamblers as well. But gamblers being gamblers are never satisfied and most will try to win even more which results in heavy losses. For every successful gambler there are at least 100 who fail constantly.
Of course it's a business. Like Netflix is a multibillion dollar entertainment business.
Gambling may be "profitable" for
some (random) gamblers but that is a matter of luck. I think you're right, people usually don't quit while they're ahead and eventually lose, then lose even more trying to win it back. It's a different discussion tho... from the probability point of view the chance of winning or losing would be exactly the same even if people were extremely disciplined and walked away with the winnings. Perhaps it would reduce the casino profits a little bit because the betting volume would be lower but it wouldn't affect the chances. The house always wins.