The killer use case has existed from day 1: remove the middleman. That is banks, or goverments. That's it. There's literally nothing else to it.
Speculating on its value, while possible, has nothing to do with its purpose.
And yet here we are, discussing a Bitcoin ETF, which involves plenty of corporate middlemen and has no benefit to the Bitcoin community besides increasing Bitcoin's speculative value.
And I’m sure plenty of other people were buying and holding in exchanges like Coinbase already, instead of buying bitcoins in direct person-to-person cash transactions like the decentralization advocates imagine they will
Its purpose is to provide an escape hatch from fiat currency that steals people's wealth, available to everyone in the world, ultimately shutting down the global scam that is central banking.
It is the hardest money that mankind has ever seen, digital, with an issuance schedule that is set in stone - no select few people have the ability to effortlessly print it, stealing the wealth of the rest and corrupting the world at its core, causing third world poverty, endless wars, corrupt media etc.
It's very healthy to listen to both sides of an argument and theorise about conspiracies. It's the close-minded people programmed to laugh at them who need to self-reflect.