> The rewards are usually pretty good and as long as you pay off your balance every month, you're getting ~3% of your purchases back in rewards/credit

So far as I’ve seen, most credit cards issued in Europe don’t have huge rewards like that because card networks are capped in how much they can charge merchants for card processing. Add into that a penchant for not acquiring open-ended (revolving) debt, and there you go.

Remember that those rewards in the States are paid for by relatively high processing fees charged to merchants (2.5% plus a flat fee of around a quarter) and the interest paid by people who carry balances. And that interest rate is regularly in the low to mid 20% annual rate range.