Do you know a blockchain that does not use at all cryptographic primitives standardized by USA or other countries? It is strange to me that the security of many cryptocurrencies is based on ciphers, hash functions, elliptic curves, etc. from American standards.
It is normal when a cryptographic product contains standardized primitives of a certain country to be sold in this country. However, cryptocurrencies are considered an international tool completely independent of governments.
There is a small, but non-zero chance that a backdoor was included in one of the standard primitives. That is why it is desirable for cryptocurrency developers to avoid such primitives. At the same time, I understand that developers may fear to provide their own primitives, because they may be broken by accident.
Therefore, the only solution is to use provably secure cryptography. I wonder why the cryptocurrency society ignores provably secure primitives. Of course, they are slower. However, they don't seem to be a bottleneck in comparison with complicated (pairing-based) protocols often deployed in blockchains. If some of the cryptocurrencies are completely free of American origin, then this may be their advantage with respect to others. Thereby, their cost should be greater other things being equal.