Though exciting, looks like there's still room for shrinkage, the linked article puts a bare-minimum gzipped @zod/mini at 1.88kb, while Valibot is at 0.71kb [1].
Can you, please, share a source for the claims you make about Marian? Specifically, "developed and open-sourced by a US multinational, Microsoft" and "funded by MS" (from two other comments by you)?
It does look like Microsoft is (was) funding the project, and employs one of the authors as head of research at Microsoft Translator, which is great, but all the "seed" funding and actual research happened in EU. Microsoft hired the author only in 2018 [1], while the earliest EU grant was allocated in 2015 [2], and the main paper they published says "it has mainly been developed at the Adam Mickiewicz University in Poznan and at the University of Edinburgh" [3].