....Also, one thing that people keep telling me and get me cornered with is that there's no actual value behind Bitcoin. And that the economy can't function like that. Making Bitcoin only requires resources (e.g. energy, machines), but Bitcoin doesn't give anything in return. They say that behind the fiat there's an actual value, which is why we can avoid inflation: precious metals, country resources, plus it is fixed to the GDP, which is why the economy can be stabilized.
Without that - fiat is just paper. And while Bitcoin has nothing like that fixed to its price - it is also nothing.
I haven't really encountered anyone saying it's a pyramid scheme but the main argument is it's not backed up by anything. It's hard to argue with people who are stuck with the mindset of traditional investments and businesses. They love to compare BTC to stocks that's backed up by a company or to fiat that represents a country's reserves. They'll never accept if you say BTC is backed up by the Bitcoin network and its value can also be derived from the cost of mining or what the market dictates.