So basically, your argument is that an empty box that someone sold you for $70K is not actually empty. The trading act magically make a valuable product, an asset to appear in it? Although when you open it you see with your own eyes it is still empty. You know how this is called? Being naive, gullible and delusional.
It seems like you are very skeptical of this but, that's okay, I just want to ask what about fiat whose value is agreed, Is BTC no value and just an empty box if you buy it today for example with a face value of $ 500 only, then you test selling on the exchange you buy at the same time whether your money will be lost to the earth in your account, If possible, do it today.
I'm probably not very technical and like to just get straight to real applications.