I wonder why traders on those argentinian exchange don't just switch to internation exchanges like Binance. If bitcoin is trading at a premium of $10k++ when it's only around ~$9k+ on the global market, why buy premium?
I think arbitrage can't be done if they're limiting exchanges users to argentinians but on the flip side why don't they just buy cheaper from global markets.

Because Binance doesn't accept the argentinian peso. They'd have to somehow buy dollars FIRST before using Binance.
And the problem in Argentina is that you can't get hold of dollars.