what could be some of these countries that are in high demand of Bitcoin or USDt & how can we leverage on arbitrage opportunities?
Try looking for more information about "Kimchi Premium"
[1], that is the term for the South Korean market which offers higher prices than globally. I don't know whether this phenomenon still applies today, and also whether non-natives can access exchanges that have exclusive prices and then allow you to transfer cryptos in and out.
1.
https://corporatefinanceinstitute.com/resources/cryptocurrency/kimchi-premium/Let me check this out! Thanks.