The only strategy that can beat the house is to quit while still winning profits. This way the house can't have the chance to recover the winnings of the player. And best if the player withdraws it and use it elsewhere worthy.
The question is how much profit is enough to quit gambling completely? Most gamblers try to earn huge profits to try and change their lives, but they end up succumbing to the house edge later on and screwing themselves in the process.
Very, very few gamblers get extremely lucky by winning huge amounts and some of them quit gambling as you mentioned and invest elsewhere.
I do agree that there is absolutely no way that you could make any profit at all without luck. No strategy can give you a profit, there is no strategy that can mathematically bring you any profit at all because there is house edge and that means mathematically speaking there is absolutely no way anyone could ever make money on the long term.
The only possibility would be that you could get lucky time to time to keep you at the profitable margins for the long term, I do hope that people do stay at at least break even point but at the same time that means I would like this casino to bankrupt, what would happen if nobody ever loses money? That means casino makes no profit, in that case it would bankrupt if we don't lose.