Rationale/reasons for splitting Sign and Authenticate into two separate subkeys in a work-environment?

[Philihp Busby]

On 2020-12-22T13:31:42+0100 Christian Chavez via Gnupg-users 
<gnupg-users at gnupg.org> wrote 2.8K bytes:

>I'm currently helping my workplace test out Yubikeys - to see how/if 
>they could help us with our software development. One expected benefit 
>is to allow developers cryptographically sign Git commits/tags (e.g).

I hope I'm not the only one on this list that may have left innocuous 
commits forged under the name of someone who didn't work there anymore 
to prove that a less ethical person may have already gotten away with 
actually committing malicious code.

I was in an org once that had a neat system of generating SSH keys on 
hardware tokens, and then distributing them to the servers that each 
person should have access to. It was hella cool.  I did something 
similar with my home LAN by swapping ssh-agent for gpg-agent on my 
terminals, and using a keyserver to distribute my public key to devices.