The best way is to just backup to multiple locations and actively manage it. RAID at the backup destination is nice because it means that if a disk fails, you don’t immediately lose everything there. But if you have multiple places where that data lives then it’s not the end of the world to just re-create the backup.
If you want to get into true archival solutions(way more expensive than setting up a RAID) then you’re looking at things like M-Disc and LTO tape
Rightsholders have to compete with pirates, but the inverse is true too.
Pirates typically win on price, but if they deliver a sub-par product, or make it more inconvenient to access, then it makes sense to go through official channels instead.