It is complicated.

On one side companies sometimes have policies on the appearance of their client-facing people due to wanting to project the kind of image some customers expects (humans in general are pretty superficial in passing judgement, even when they’re supposed to be hardnosed professionals) rather than because people inside that company actually care about it.

On the other side, this stuff is widelly abused in the highly hierarchical structure which is the typical company to very visibly demonstrate the power of management through making the most visibly free-thinking employees comply (or leave, they don’t care: the purpose is for it to be seen by the rest).