Consumer protection laws in the US have come a long way in the last 30 years, it's the reason that security features on your credit card have continually grown (cvv to chip to text messages about purchases).
It used to be that if there was a fraudulent charge on your credit card, the agreement you signed with the credit card company meant that you had to pay it. That's why you hear horror stories of things like bankruptcy over a stolen card. But these days the law says that a consumer cannot be held liable for a fraudulent charge unless they facilitated the fraud. The CFPB is a government agency specifically dedicated to protecting consumer finances, given teeth in many areas after the 2008 housing crisis and predatory lending. But even before that, credit cards in particular were targeted for reform.
So, the reason that credit card companies are hyper vigilant is because it's their money on the line. They have a major incentive to prevent fraud that they didn't have in the past. What ends up happening then is they shifted this to their merchant agreements to offload some of their liability. They can't completely offload the responsibility (which is why you will still see them try to prevent fraud) but in many cases they will try to shift the liability to the merchant by reversing charges and essentially taking their money back. However, there is a short window of time available to do this, so it’s very possible for a credit card company to have to use their own money in a fraud case. This generally makes them care about fraud.
Interestingly, in one of the few cases in the US where this is true, businesses do not have the same fraud protection afforded to other consumers. Businesses can still be held liable for fraudulent charges on their card. Although, since it's the same methods in either case, many credit card companies blanket their fraud protection methods and policies. Still, it is much easier to dispute a credit card charge as a consumer than it is as a business.