I had the opposite experience I had two Australia - Europe trips booked totalling 8 months before covid hit. With the multitude of refunds I made money on exchange rates with some and lost with others. I think I probably ended up ahead.

The airline probably doesn't even know the currency you paid in, they just received an amount in their currency from the credit merchant. Ditto for the refund process.

Be thankful you got a refund rather than a voucher not worth the paper it's printed on (eg. Air Asia) or a legal, stamped contract probably of a similar value (Air Armenia).