I used to do the separate drive thing for ages, but haven't in recent times. SSDs are too small for data storage, NAS systems offer better storage options than desktops.

I just use a regular directory called "data". That data directory is monitored by SyncThing on my desktop and laptop. I also have SyncThing on my phone, which shoots all of my photos (one-way) to a subdirectory in the Data directory. Additionally SyncThing syncs the Data directory, one-way, with file versioning, to a TrueNAS server sitting at one of my other homes, with snapshots enabled.

That directory also gets backed up locally, nightly, to an encrypted archive, to an external drive, which gets pushed out to Backblaze's B2.

All of my video stuff is on external drives due to size, encrypted locally, pushed out to Backblaze's regular desktop backup service. I love B2, but don't want to pay THAT much for my little 4K GoPro / phone videos.

Is this foolproof? Nothing is foolproof. I once went through 6 layers (3 physical systems, each had a primary and backup mode) of systems redundancy in one failure, with each of the 6 layers fail due to a different reason. BUT, this setup gives me a fighting chance. In the case where I blew through the 6 layers, the remains of each layer helped me bring everything back online within an hour.