It's not iCloud Photos, in my case it's Google Photos. But I keep a copy of all my photos in a self-hosted instance of Immich [1], which I then back up to a Hetzner Storage Box using Backrest [2].

So I end up with 3 copies of all my photos, on 3 different providers (I mean... 2 different providers plus my homelab disk).

[1] https://immich.app/ [2] https://github.com/garethgeorge/backrest