What filesystem is currently best for a single nvme drive with regard to performance read/write as well as stability/no file loss? ext4 seems very old, btrfs is used by RHEL, ZFS seems to be quite good… what do people tend to use nowadays? What is an arch users go-to filesystem?
Yes, there are some limitations to be aware of, with how it interacts with certain features. But EXT4 doesn’t have any of those features at all. It doesn’t have CoW, or balance, or multi-device, or snapshots.
If the filesystem, is single-device, and you have the swapfile on it’s own nocow subvolume, preallocate the swapfile, and don’t try to take snapshots of it, it should be fine.