Why Do UK Credit Cards suck compared to the US?

Is it just me, or do most UK credit cards seem to offer next to nothing in rewards? Why?

I keep getting finance videos on YouTube from US creators, and it feels like they have a ridiculous number of cards with amazing cashback, sign-up bonuses, and travel perks. Meanwhile all the major banks here, the rewards are just… depressing?

I’ve got an Amex BA card - and am considering upgrading to the premium or gold, but I’m running into more and more places that don’t accept Amex. Are there actually any good alternatives, or am I stuck with an M&S card that gives 1 point per £5 spent? Surely there’s a better way to maximise rewards here?