Indeed. "S3 compatible" is the state of the art for object storage imho. As long as you can talk to a storage system that supports the basic S3 primitives, longevity is improved and there is no lock in. You can use S3 proper, Backblaze, Wasabi, Backblaze B2, local storage exposing an S3 api, etc. Any replacement is mostly drop in assuming it can read, scan, index existing objects.

Edit: @n3t heard wrt to the turn of phrase