The fact is that the number of millionaires and billionaires increases each year, unfortunately at the expense of the majority of the world's population, but it is the world we live in. There is a chance that some of them will want to have at least 1 BTC, but we can not compare that with expensive watches, yachts or private jets, this is something that is definitely shown to others as a status symbol. I doubt that some millionaires would brag about how he have some bitcoin, that's what everyone can do just by make some watch-only wallet with any amount of coins.
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But that's not how most of them act. Being able to buy a high quality replica of Rolex watches for $200, which is impossible to tell from the real ones by sight, they are buying genuine Rolex watches for $20,000. Those people would better buy a real BTC to brag about it rather than show a fake amount of coins in a watch-only wallet.
So, I still count on eagerness of the rich to brag about exquisite things they have. And Bitcoin is definitely an exquisite thing.