At the company I work today, looking at some repositories from hardware and firmware engineers I found this folder structure.

project_root
| - 1.0
| - 1.1
| - 1.2
| - 2.0
... and so on

We had a guy who never really used git and his project directory on his computer had backup_1, backup_2, etc. Once he left, the boss declared not using git would be be a fireable offense. 2 years later we are still finding pieces of functionality that we don't have source for.