The commutative-monoid enrichment of a semiadditive category remains only a sourced remark here

Every semiadditive category is enriched in commutative monoids. The already-published theorem A category with finite biproducts is enriched in commutative monoids proves this implication, and Semiadditive category records the underlying ordinary notion. The converse needs the additional existence of a zero object and finite biproducts: enrichment in commutative monoids alone only supplies commutative-monoid homs and bilinear composition.

This page keeps that comparison as a remark rather than promoting it to a local theorem, because the present batch's harvested enriched-category sources are Kelly, Riehl, Cruttwell, and the enriched-adjunction appendix, and none of those sources was harvested here as the direct carrier for the full semiadditive/$\mathbf{C}\mathbf{M}\mathbf{o}\mathbf{n}$ equivalence.