Is this the recommended way to use time machine then, as opposed to over a network?

> If you have a USB drive or other external storage device, you can use Time Machine to automatically back up your files, including apps, music, photos, email, and documents.

* https://support.apple.com/en-ca/104984

The "3-2-1" strategy is even possible if you rotate drives between locations:

> For extra security and convenience, you can back up to multiple disks. If you work in two locations, you may want to keep backup disks in both places.

* https://support.apple.com/en-ca/guide/mac-help/mh40739/mac