Usually that is true, but not every single time. You could get a lot of losses that will eventually make you run out of money and there is no return from there, it just doesn't work like that. I have seen people turn just a few dollars into thousands of dollars and then end up losing it all back again. Casinos have house edge on their side which means that it would not be possible for anyone to just keep on gambling and win.
If you gamble long enough, then you are going to end up with a loss eventually and that is the end of it, that's just going to be the case for sure, without a doubt. I hope that it gets to a point where it will not be possible for anyone to just keep on gambling for a long time and still not face 20+ losses in a row, if you keep gambling, you will reach that one day.
Reaching 20 losses in a row is not much, I have seen up to 40 losses in a row , that when I was playing at that time I came to think that the casino did not want to let me win more and that they were signing me up to lose, but then I began to Investigate about the probably fair and from there a great interest came from many people who wanted to beat the system, and remembering those times where I played so much, I wonder if the AI in the near future if it has that capacity, because it is not difficult for it nothing to learn, it is a matter of days , for you to Learn something at a master level.
Then there's the confirmation bias, if we start to think that we are losing unnaturally lot, we start to notice every loss and our brains is wired so that it's telling me that we are doing something wrong or the game is rigged. Somehow we tend to forget that if there's a chance to won a lot, there must be a chance to lose as much and more. Somehow we don't think the game is rigged if we win a lot.
If you play long enough entually there will be a day when huge amount of your bets are going to be a losing bets in a row. It's just as certain that there will be a day you will win big. That's just probability statistics.