What benefits are user avatars offering?

Lets say you have a website that has absolutely no social interactions between the users, your users usually visit the site to use different tools they get offered by being a member or read up on different topics regarding their daily working-life. If there is interaction with different people its usually just the support team if they have any questions or need advice.

Right now we have a website that displays the logo, the navigation, a search function and the name of the user with a link to his account informations.

I am currently redesigning the header and one of my first thoughts was to give users the possibility to upload personal avatars to the site which then get displayed in the header next to their name after they logged in.

Of course i would provide neutral default avatars if they don't want to upload a picture and it would not be mandatory.

Right now i am asking myself what the benefits would be, what does the user gain from that option? Customisation is important and gives a nice vibe/feel, but what other selling points would you point out if you would have to pitch this in front of other people? And more important, are there any possible disadvantages regarding UX?