IMO the author tag helps in situations where the code is visualized on a non IDE place, like on GitHub, Bash CLI or tools like notepad++, the tag here gives a direct help about the origins of the thing (interface/class/method). The VCS is helpful but it requires learning curve and IDE.

From another perspective, the author tag may help in enforcing the Open-Close principle in SOLID, for example when a developer comes to touch an interface marked `@author <senior_developer>`, they'd think to not touch it as it was designed by a high level person, so maybe that touching it, may ruin important things, eventually, they will think about making an extension of it, which is great.