Calling legal tender "a completely made up concept" is also an extreme opinion. Try paying your taxes or mortgage or car loan in anything except legal tender and you will soon find otherwise.
I said gold isn’t INTRINSICALLY valuable. That’s a very important part of the phrase when people talk about gold as money. They, and you, like to say it is INTRINSICALLY valuable. But it isn’t. We have DECIDED it has value, but that value is NOT a part of its essential nature (in·trin·sic
/inˈtrinzik/ adjective belonging naturally; essential). If human being had never decided that the soft metal that shines up nice but was never actually useful until alloying was invented, and even then didn’t get really useful until printed circuits were invented was pretty it wouldn’t be valuable. It has the value we gave it. Nothing INTRINSIC about it.
Legal tender IS a made up concept. Nothing extreme about that. There’s lots of ways to pay stuff without legal tender. Ever heard of stock buyouts? Or maybe go hang out with the sovereign citizen crowd? Ever used credit card miles? And really, let’s keep in mind, the vast majority of the purchases we make now are not with printed legal tender. It’s 1s and 0s we’ve decided to PRETEND represent legal tender. I pay my mortgage with a monthly EFT. Same way I get paid, we twice a month on that. Last time I owed taxes EFT, when they owe me, EFT. I’m going to a concert tonight, ticket bought with a debit card. I had lunch delivered, GoolePay to hit the debit card. I would say about the only people who use actual legal tender anymore are drug dealers, but even they prefer electronic money now.
Not only is legal tender completely made up, it’s also dying. There’s so many better moneys out there now.