For USA cardholders and rentals in USA, perhaps. There's a whole bunch
of people for whom neither applies.

Interesting. Not even American Express?

Nope. I checked, my UK Amex card doesn't have car insurance.

If credit card companies in your country aren't competing on services,
how do they distinguish themselves so you'll obtain theirs?

The compete on plenty of services, just not that one. US credit cards
all suck because none of them include trip cancellation insurance,
like all UK cards do.

R's,
John