Ok. I'll accept the fact you can't send me BTC. It does not exist for you. That's fine with me. Have a nice day.
Nobody is able to send you BTC. Only symbols for it. BTC exists only in imagination, only in the human mind. Everything else traded in the market exists outside of the human mind (equity, debt, labor, services, cars, buildings, land, etc.). Given that Bitcoin exists only in imagination everyone defines it differently. Some even view it as a shiny coin which is why they create pictures of it.
But you won't risk somebody buying you coffee with it? And by the way admitting that zero is a human concept you have to admit that Bitcoin is a human concept. And we find zero quite useful don't we? Pretty good for something that's a representative of nothing!
We can make 0 and Bitcoin equals. Since they are both representations of nothing. According to you.
No, they are both concepts. They don't actually exist in reality outside of the human mind. And both concepts can be represented with symbols: "zero", "0", "bitcoin", "btc".
I can't believe people actually think about bitcoin like this

as if they are so smart that they realize that a bitcoin can't be physically held. I don't think this person would think this way about gravity or physics or love or brand value or other "intangible" things. Whether something is "real" or not is just all perspective. By this logic the US dollar is certainly not real either. Probably even less real than bitcoin.
Debt also can't be physically held. But it exists outside of human mind. US dollar is debt. This debt is represented with symbols "USD", and numbers. Debt is real. It is explained in the OP how it is created and how it is paid.
You claim BTC does not exist. But you also acknowledge that Zero Doesn't exist.
Since Zero and BTC are Both non existent how can we even think about such things if they do not exist? You/We clearly do think that Zero not only exists but has great value. You can apply the exact same logic to BTC. You cannot get around this argument since you have already said zero doesn't exist either.