It DOES matter. Here’s an example because you don’t appear to understand budgets or expenses:
A Syrian family needs to pay rent and buy food across the month. Rent is equivalent to $200/month. Groceries cost about $90/month.
Household income is equivalent to $300/month. If the family buys Bitcoin with all $300 of wages and the fiat exchange rate drops 15%, they may not be able to buy enough groceries to feed the whole family with only $55 remaining. All-in Bitcoin is too risky for tight budgets. Many low income people have tight budgets.