Are you referring to the Diners Club "Restaurant Savings Program" of about a decade ago which gave 20% discount for dining only at certain restaurants? That was through RewardsNetwork, and the same company still operates restaurant programs, but not any tied to a specific credit card any more.

However, that didn't "pay for" restaurant charges, that only discounted restaurant charges any more.

I've had the Diners Club Professional (USA) card for some 15ish years now, and I recall a way to pay the annual fee with points, but not to pay for restaurants specifically with points. (But all those ways Diners Club used to have to pay for stuff with points were rather poor value, compared to transferring Diners Club points to airlines and/or hotels.)

There are various cards that give you the ability to redeem points for gift cards for certain restaurants. But again, those are all poor value, not necessarily even as good value as 2% cashback card.

So I'm confused by why you're so focused on paying for restaurants with points, without considering the value of using the points for that versus using them for something else.

Points/miles are most valuable when used for "excess capacity" inventory like airlines seats and hotel rooms. When used to repay stuff, the card has to pay "hard cash" to pay down something on your bill, which is why it's never much better than an ordinary cashback card would be.