So, one of the MAIN reasons people use a different partition for /home is so that /home is not affected by a catastrophic failure of the “system related” partition(s).
But that does not mean it has to be on a separate drive. Though, that is a good idea.
On our single drive machines (like a laptop), we use a separate /home , formatted as XFS.
The system is BTRFS.
On the desktops, one SSD is partitioned and formatted as BTRFS for the system partitions … a second SSD is dedicated to /home, formatted as XFS.
We back up /home’s weekly.
We don’t worry about backups for the system.