I do really believe gambling sites will try their best to somehow win back profits. What is your opinion?
They will, it's called the house edge. No casino is in it to lose money and the odds are always in their favor. Now if you are worried about losing the funds you have on that site - your bankroll - to anything but more gambling then you don't trust the site and should leave.
Now if you trust the site, there is nothing wrong with continuing to gamble, just remain at the stakes your bankroll can support. If you significantly increase your bankroll with wins then you could presumably increase your betsizing if that's what you care to do, or just keep it the same level if that's what you enjoy.
Me personally, I pull some of the win out so that I reap the reward and let the rest sit on the site - I trust where I game - to handle the variance and downswings. This way I have taken profits, and can still reasonable play well into the future if I hit a losing streak without having to deposit again.
Some people think that there is a systematized software in a dice or blackjack that is why they often stop and some people have their earning targets so they also often stop or some people have a daily target and they have to stop for that day which is good for getting some mental relaxation.
If someone thinks that a site is targeting them and they continue to gamble there they are fools, simple. Either the site is provably fair and they are foolish to think they can't loose, or the site isn't provably fair and they are fools for playing there.