Currently have 2 1tb NVME's over around 6 tb of HDDs, works really nice to keep a personal steam cache on the HDD's in case I pick up an old game with friends, or want to play a large game but only use part of it (ie cod zombies).
Also is super helpful for shared filesystem's (syncthing or NFS), as its able to support peripheral computers a lot more dynamically then I'd ever care to personally configure. (If thats unclear, I use it for a jellyfin server, crafty instance, some coding projects - things that see heavy use in bursts, but tend to have an attention lifespan).
Using bcachefs with backups myself, and after a couple months my biggest worry is the kernel drama more than the fs itself
I'm curious what type of workflow you have to utilise mainly the sane data consistently, I'm probably biased because I like to try software out - but I can't imagine (outside office use) a loop that would remain this closed