In some cases it's hard or impossible to distinguish D&D tabletop content from overall franchise content.
Consider post #7678504: Shar, a goddess in the Forgotten Realms setting. (We used to have a forgotten_realms tag, but it was aliased to the main D&D tag in topic #26433.)
We currently have Shar tagged as as shar_(baldur's_gate). However, Shar was first mentioned in the Forgotten Realms Campaign Set, a boxed set for the D&D 1st edition tabletop game published in 1987. She's also been written about in a lot of tabletop content since then, plus some of the Forgotten Realms novels, and despite how we tag her is very clearly not a Baldur's Gate exclusive character.
If we made a tag for D&D tabletop content, then got pedantic about Shar and liberated the handful of pictures of her (which aren't self-evidently related to Baldur's Gate, e.g. by also including Shadowheart) from the Baldur's Gate 3 tag, would we then move those pictures over to the tag for tabletop content? At least if we punted Shar into dungeons_&_dragons, she'd be in the grandparent tag for Baldur's Gate rather than a different branch of the hierarchy.