I can only answer for Garage and not others. Garage is the result of the desired organization of the collective behind it: deuxfleurs. The model is that of people willing to establish a horizontal governance, with none being forced to do anything because it all works by consensus. The idea is to have an infrastructure serving the collective, not a self hosted thing that everyone has to maintain, not something in a data center because it has clear ecological impacts, but something in-between. Something that can be hosted on secon-hand machines, at home, but taking the low reliability of machines/electricity/residential internet into account. Some kind of cluster, but not the kind you find in the cloud where machines are supposed to be kind of always on, linked with high-bandwidth, low-latency network: quite the opposite actually.

deuxfleurs thought long and hard about the kind of infra this would translate to. The base came fast enough: some kind of storage, based on a standard (even de-facto only is good because it means it is proven), that would tolerate some nodes go down. The decision of doing a Dynamo-like thing to be accessed through S3 with eventual consistency made sense

So Garage is not "simply" a S3 storage system: it is a system to store blobs in an unreliable but still trusted coonsumer-grade network of passable machines.

Minio assumes each node has identical hardware. Garage is designed for use-cases like self-hosting, where nodes are not expected to have identical hardware.

performance, therefore cheaper