The dollar is representative of the work you contributed to the economy

If that’s true, nobody on Social Security Disability would be getting money.

So basically, the more people who believe in the value of some thing, the more that thing holds actual value?

Yes. That’s how value works.

https://en.wikipedia.org/wiki/Paradox_of_value

The paradox of value (also known as the diamond–water paradox) is the contradiction that, although water is on the whole more useful, in terms of survival, than diamonds, diamonds command a higher price in the market.

Real money is backed by a country’s respective economy

True.

its an IOU from the government

False.

An IOU from the government is a bond.

If someone says something that a lot of people want to be true with no evidence… it ain’t true.