You forget one very important thing, and that is the fact that fiat does not have a max supply, and it should not be forgotten that someone adds trillions of dollars to the system, which then buys Bitcoin with a part of that money. The difference between you and me is that we will always have limited purchasing power (unless we win the lottery), and they will always have their own money printers.
It should also not be forgotten that stable coins like USDT and their digital printing without being really backed up with anything pose a kind of problem, but that is another story nonetheless.