It's easier for San Salvador to disappear Bitcoin into cronies' pockets than U.S. dollars. For this purpose, Bitcoin's deeper liquidity makes it the best choice. Less cynically, Bitcoin has brand recognition. That makes it politically palatable in a unique way.

Bitcoin isn't a great currency. But it is a competitive store of value. El Salvador doesn't have a trusted domestic market of financial assets. This is an experiment in replacing a domestic market for assets with Bitcoin.