You can't do that with crypto either.
Because you actually need to convert your Fiat into crypto first.
The current limitations are real and the theoretical possibility is equally good of what currently exist: a black market.
In Iran everyone took euros or exchanged them on the spot. Even when the currency shop was closed people were waiting outside for us
Yes, this is due to regulations, but it's also due to the centralized nature of the technology which requires permission to use.
Even when more regulation is forced onto cryptocurrencies, the architecture will always be permissionless, as it's a decentralized network. That is a fundamental difference.