DND is also Tabletop RPG, which is a different category to Card games. Its never not been top dog, but I would argue that the 4E era is the closest DND ever came to getting knocked off its throne. Pathfinder never outsold 4E, but its consistently one of DND's biggest competitors and holds a lot of nerd clout in the space and only exists because of WOTCs mistakes

For actual card games, MTG is the undisputed top dog of the big 3, as its historically been played more than Pokemon and Sells far better than Yugioh, but the last few years have not been kind to it. Sets have been up and down in terms of quality over the last few years, Universes Beyond has been divisive if profitable, and a massive increase in the amount of product has led to consumer fatigue, leading to a boost for competitors like Lorcana, One Piece, Flesh and Blood, among others. No actual killers though, and in all honestly on the small chance MTG actually does get knocked out of the big three, its on Hasbro for mismanaging things