It is however more of a mitigation for bad distro installers than general good practice. If the distro installers preserved /home, you could keep it all in one partition. Because such “bad” distro installers still exist, it is good practice if you know that you might install such a distro.
If you were installing “manually” and had full control over this, I’d advocate for a single partition because it simplifies storage. Especially with the likes of btrfs you can have multiple storage locations inside one partition with decent separation between them.