One challenge is assembling everything into a coherent whole, since the same informal concept can be formalised in slightly different but incompatible ways.
Probably this will be done in some form in the coming months.
Metamath has done quite a bit or primary research into this. Theorems often have a slightly non-standard, but more general form.
One can ask things like, "what is the equivalent of functional programming?" Or, "is there global state?" It's a perspective on reverse mathematics.
Note that mathlib currently includes duplicates of many theorems; I believe deduplication is an active goal (if not one seeing much labor right now).
LLMs can do smarter searches, and will likely find proofs for most of them, but are not guaranteed to find a proof.