That's true, but the issue is, what if you've been Preferred for years, and yhou didn't archive the T&Cs from back then?

In my case, I've been Preferred for about a decade, and I have no clue what the T&Cs did or did say about payment currency back then.

There is no guarantee that the T&Cs online now are the T&Cs that were online at the time you signed up.

In my case, I've been Preferred so long, that it long predates foreign transaction fees. For at least several years after I joined Preferred, the only kind of foreign fees were foreign currency fees. DCC wasn't as "evil" back then as it is now, because it at least allowed you to earn points/miles on your card on Avis' converison fees, which you wouldn't if your points/miles-earning card was the one that added the foreign currency fee. It was only once foreign currency fees were replaced by foreign transaction fees that DCC became useless and "evil". By again, my Preferred T&C were from many years before that!

But in my case, being US-based, I was able to call up Avis and get the DCC removed (though it did take multiple calls and then some time, they did eventually do it). In the US, the department which did was not a department I could call directly (in the end, that department called me and left me a voicemail to let me know that they had made the change).