Indeed.

And you get a massive return for investing in dollars, if your own currency has say hyper-inflation.

"I exchange my local currency for a USD and in a year when I want to buy something I can exchange it back for twice as much local of currency"

Not massively different to investing in BTC today, in the hope that you can convert it back for more of your local currency when you want to spend it.

> in USD and USD investments

What's a USD investment?

People want USD because of it's transactional value (i.e. they want to trade with it), not to use it as a store of value

First, a USD-denominated investment is not the same thing as an investment in USD. Second, I am from "other countries" and no one around here is investing in USD. Can you point me to a specific example of people from other countries who are investing in USD? Thank you!