The problem of Sri Lanka and poor countries is not a fiat or payment method, the problem is that these poor countries are usually highly corrupted, there is no freedom of business and there is a monopoly on many things, there is a lack of educated people in country and another bigger problem is that one may find job via nepotism instead of education and skills.

Education is really important. If you have a lot of money but don't know how to use it, then it's just an invaluable paper. Bitcoin is not a magic thing that automatically grows. Look at it like a pool where each bitcoin proportionally represents the money that's in the pool. The more money we put, the higher the value but when we take out money, then value decreases.
I don't think that current pressure on Bitcoin payment adoption in El-Salvador is the best idea, nor is it performing well because people should have access to computer and internet and know how to use them in order to move on bitcoin payments.