I did try seaweedfs ~half a year ago and I had issues with setting up users through terraform module (if I recall correctly, users endpoint were not correctly responding on delete), and lack of S3 expiry rules (you needed to use seaweedfs configuration or API for that). Other than that, I was pretty happy with it.
Because you want to mock the tools you are going to use in production locally or in CI. Really good reasons to not totally change what you are doing in your app between environments.
https://garagehq.deuxfleurs.fr/
This post does not even mention the S3 API as a replacement for a filesystem.