Satoshi's whitepaper is titled "Bitcoin: A Peer-to-Peer Electronic Cash System". Cash.
Tax authorities squashed that around 2014 when they started classifying it as a capital asset rather than cash. Nobody wants to track their cost basis and write a tax return line item for every coffee that they purchase throughout the year. Enthusiasts like us will use it anyway - either jumping through the tax hoops, or ignoring them - but most people in functional economies will be good citizens and use the money that their government tells them to.
It's still been a huge success as a store of value, akin to gold but without the problems of physicality. Nothing goes exactly as planned - it's silly to call it dead because it failed to completely live up to its original intent. But it is also ahistorical to claim that it was never intended to be cash.