The OP is forgetting that in many places they accept bitcoin as a payment method. the person takes their bitcoin and buys things or goods and services, I for example take my bitcoin and I can buy top up for my cell phone, so that means that bitcoin is a currency and can also be used as an investment asset In the long run, this will depend on each person and the options people have for being able to use bitcoin as a payment method in the real world. OP, he's saying things for feelings, he must have had some kind of disappointment with bitcoin and it made him hate bitcoin to the point of posting things without first calming down and thinking more clearly
As you said it makes a lot of sense, because FIAT money is just a piece of paper, while gold is just a yellow metal, but all of that becomes valuable when many people want these items and depend on them to live, like people depend on living with FIAT currency. ,
people may also need bitcoin in case they want privacy and let's suppose someone wants to travel to the US and that person has 1 million US dollars but that person cannot travel with all that money on the plane this person doesn't trust the bank so this person can buy bitcoin worth 1 million dollars and then travel and when he arrives in the US spend these bitcoins worth 1 million US dollars. bitcoin has many advantages