On what grounds do you believe the value of BTC is meme-driven? Another (and arguably more plausible) explanation is that the price reflects the vast amount of criminally-obtained wealth stored in it. It’s a far better store than burying cash in mountain caches.
All money is meme driven. Money is fundamentally a meme itself. Seeing lots of people who seem to be making some sort of implicit distinction between bitcoin and USD and so on, but they are no different. They serve the function they serve because of what people believe about them, like any other social, cultural, or economic abstraction. Bitcoin has the feature of a verifiable ledger, but its value and function are in our heads, just like the USD or GBP.
BTC is a terrible place to put criminally-obtained wealth. Public ledger and all that makes it very difficult to hide anything.
That ship sailed long ago, before there were viable alternatives to BTC. There are plenty of ways to launder BTC (i.e. hiding in plain sight) and the existence of hoarded wealth in BTC isn't necessarily exclusive of other cryptocurrencies that are better fit for purpose.