The most logical reason is that they want to connect the human identity to the wallet/address, thereby easily removing anonymity and ensuring the government can monitor their population effectively
70% of El Salvadorians don't have a bank account [1].
[1] https://datacatalog.worldbank.org/dataset/el-salvador-global...
It was alleged this move would let percent "removing anonymity and ensur[e] the government can monitor their population effectively" [1]. Counterargument was that "normal banks already do that" [2].
That is true. But 70% of El Salvadorians don't use "normal banks." They use cash. Cash does not "ensur[e] the government can monitor its population." This Bitcoin rollout does.
So yes, an El Salvadorean using a bank to do business and switching to Bitcoin gives up no privacy. But one using cash does.