The people in Lebanon, Turkey, Venezuela holding USDT on Tron would hard disagree with your statement.
There are capital controls in place in these countries that make holding foreign currency simultaneously difficult and illegal.
This is why I believe a US CBDC and CBDC wars are highly likely.
A CBDC allows nations to control those nations that use their currency and the increasing it’s use allows the issuing nation to debase the currency to their advantage.
The only problem is distribution of technology but this is only a matter of time.
There are at least a dozen 'very solid' currencies that people anywhere should be able to transact in, notably the USD.
All of which you 'own'.
If there are helpful things they can do, 'digital' currencies, especially USD, (one that is not mess) would be imminently useful.
If you thought the 'petro dollar' was a big thing wait until the 'digital dollar' and entire economies de facto switch to USD.