Though MinIO could offer performance improvements here on Discourse, the forum is currently configured to store all files uploaded by users locally. Doing so keeps these files in their original format, and prevents this platform from being dependent on that one. Migrating these files to MinIO in the future is straightforward and scripted, but migrating back to local storage has been reported to be more challenging.
I have the same apprehensions about migrating Matrix to MinIO as well; however, lack of support on the non-pro version of Element makes this a moot point for that service: