El Salvador keeps buying the Bitcoin for its strategic reserve. Businesses and citizens can keep using it.
But for getting an IMF loan, IMF (which, to put it mildly, doesn't like Bitcoin) required the end to Bitcoin legal tender status.
Now the businesses are free to accept it or not instead of being required to accept it. That's all. The government plans to keep buying and using it.
The other concept is that it is a good medium of exchange. I think that is not so true because 1) its neither cheap nor easy to buy a lot of things with it 2) a thing that goes up in value is not a good medium of exchange because people don't want to spend it, they want to hoard it.
If you accept that BTC is a reasonable investment, but not a great medium of exchange then what is happening makes sense.
I am not saying that a decentralized token couldn't be a good medium of exchange -- honestly I don't know. But so far BTC is not that.
The currency itself can be used independently of its base-layer network, which is intentionally slow and costly (functioning primarily as a settlement layer). This separation is enabled by off-chain or layer 2 systems, such as the Lightning Network or custodial platforms. These solutions retain Bitcoin's monetary benefits - like a predictable money supply, off/on ramping through the base layer - while enabling fast, cheap transactions. The tradeoff is that you must trust an intermediary, but this mirrors the same compromise inherent to digital USD payment systems (Venmo, credit cards, PayPal, etc.).
In fact, USD lacks a true "base layer" altogether. The closest equivalent would be the Federal Reserve Bank’s ledger, but accounts there are restricted to large financial institutions, not individuals.