Edit: Could it also be that Amazon offer their own Mastercard credit card and they're trying to nudge people towards that?
I'd never even consider an Amex card due to my perception of it being something that many places won't even accept.
Lots of business meetings in London -> merchants need to accept Amex company cards -> people realize acceptance is high -> people look into Amex for their personal usage, for instance to enjoy higher rewards.
If you compare the rental flats with other top European cities, it’s really not overpriced.
Look at a 6k eur pcm flat in Barcelona and London, in Barcelona you will find slightly bigger flats with terrible build quality and services. In London you’ll get top quality fit and finish with excellent services.
Good luck finding a building with a decent concierge team in most European capitals. It’s almost unheard of.
Luxury product for rich people? Yeah, of course. Overpriced? Definitely not, there simply aren’t any viable alternatives to settle in.
Amex also has many more premium card with annual fees , travel perks etc which might be more relevant for someone living in London.
However, it's a charge card and not a credit card, so it does need to be paid off in full every month.
Only 2 of the high street banks offer them, and one is moving away from them.
The rest are all Mastercard.