> Object storage has zero advantages over regular block storage if you run it on yourself

Worth adding, this depends on what's using your block storage / object storage. For Loki specifically, there are known edge-cases with large object counts on block storage (this isn't related to object size or disk space) - this obviously isn't something I've encountered & I probably never will, but they are documented.

For an application I had written myself, I can see clearly that block storage is going to trump object storage for all self-hosted usecases, but for 3P software I'm merely administering, I have less control over its quirks & those pros -vs- cons are much less clear cut.