So Dankfort is a totally different scheme separated from Visa or MasterCard. Seemingly it just so happens that there are dual scheme Dankfort/Visa and Dankfort/Maestro cards and not Dankfort/MasterCard. Those cards are using Dankfort in places that don’t accept Visa, Maestro or MasterCard.
What would be needed is a Dankfort Curve card
Additionally that table in Wikipedia is outdated given the current interchange fee cap. Likely accepting MasterCard or Visa would be the same cost as Dankfort. Merchants still haven’t caught up to it or there’s not enough demand