a plugin may be you answer
https://www.flippercode.com/product/wp-user-avatar/ (Pro Paid Version)
https://en-gb.wordpress.org/plugins/wp-user-avatar/ (free Version)
This will still take some manual addition of attaching photo to user but it means you can bypass the gravatar route if you dont want to get everyone to signup to https://en.gravatar.com/ which many user may not want to do.
I have no affiliation with these plugins but have used the free version for a similar task to yours