There’s a dispute in the grounding literature over whether we should understand the grounding relation to be between just facts or propositions, or between entities of any kind. Call the latter view grounding diversity. Here’s a (softish) reason to prefer grounding diversity.
Facts and propositions, if they exist at all, are abstract objects, and abstract objects ordinarily conceived are causally effete entities. Moreover, grounding is sometimes thought of as a causal relation, albeit a special, metaphysical kind of causal relation. One could therefore argue that facts and propositions can’t ground anything on account of their causal impotency. Or, if they can, we would need a reason to think grounding is an exceptional causal relation compatible with the causal effeteness of abstracta.
But it would be a mistake to think that, on account of their causal impotency, abstracta can’t enter into causal relations at all. Some of the most compelling examples of ground involve abstracta. E.g., Socrates grounds Socrates’ singleton, Swiss cheese grounds its holes, God grounds moral truths. That in each of these cases a concrete object is grounding an abstract object might suggest that, if there is a causal problem here, it would be in cases where the grounding relation is flanked on both sides by abstracta, or where it is abstracta doing the grounding. The main point is that in any case where abstracta are in a grounding relation, there must be concreta on the other side doing the grounding, for only concreta have the integrity to be grounders,—i.e., metaphysical causes.
Of course, if you don’t accept the ordinary conception of abstracta as causally effete, this argument will have little weight.