Why do they never offer to match donations?

Why would they bother? It costs them next to nothing to stick an ad on the screen. But matching donations would be far more expensive.

Besides “matching donations” has always been a scam. These agreements inevitably amount to “Person/Org X agrees to donate up to $X in matching funds”. But $X is so small that its trivial to hit. And I’ve never heard of someone failing to get the whole amount regardless of the donation rate.