Another card sender here, although numbers have dropped a little, we still get enough to cover most of the hall. I love the bundle of cards coming in on the days we get post in December, and send mine at the beginning of December to make sure they get to the recipients in time, our post is very unreliable. There are people who live far away that we still care about, and like to exchange news with.
If you don't want to send cards any more, that's fine, but I would rather not get the mass email 'we are giving to charity this year instead', not giving me any choice in the matter. I see cards as mini presents, chosen with care and with loving messages inside. I wouldn't say to someone 'I know I usually bring you flowers, but have decided to give the money to charity instead' it would imply I couldn't be bothered. But each to their own, it would be dreadful if we all thought the same!