Is the conversion to local currency not affected by inflation? Or if you convert it to US dollars, how do those US dollars get to the country and get past capit

Is the conversion to local currency not affected by inflation? Or if you convert it to US dollars, how do those US dollars get to the country and get past capital controls? I'm specifically not asking about preserving wealth in the abstract - I'm curious about the mechanics of how it's used to put food on the table. I guess maybe the question I should be asking is, who are the people who run the exchanges and how do they work? Why are they interested in accepting Bitcoin in exchange for more liquid currency, and where did they get that liquid currency in the first place? How do they determine the conversion rate? (Are they wealthy locals who already have lots of cash holdings who want to be wealthier and are willing to sell that cash for Bitcoin at a premium because they intend to hold the Bitcoin long-term / after major political changes?)