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But, I repeat, the business model of the casino, as it seems to me, is not affected by such personal and purely individual streaks of luck, success, or, accordingly, bad luck and losses.
Of course not. If that were the case, there would hardly be a casino left on the market. For casinos, the statistics in combination with the house edge simply play a big role. For example, if a casino like Roobet has a House Edge of 10%, they win 10% more often than they lose. Of course, this also applies to each player individually: The more often a player plays, the more his individual win and loss statistics align with the House Edge.
What could happen in extremely rare cases is that a whale gets lucky and sends a casino into bankruptcy. However, I would not have come across such a case yet and you would probably actually need someone with a lot of Bitcoins ... and a lot of luck.