WordPress for websites with user registration is completely non-friendly at all. It's still a huge job to make a WP site ready for user registration/content. It's not only an avatar. It is whole system, how it works, starting with login, "backend" of user profile by default, top toolbar, default registration emails ...

Joomla is death, but WP can still learn a lot from that rest what still exist there (separation of backend - frontend, templates, modules, language overwrite, user management, user roles, menus, ...).

Joomla is outdated, so I am afraid to use it, but still considering it for some website bc. of mentioned tasks. Any kind of WP site with user content/registration required many plugins/tweaks and it's still just a tweak, not a solution - some login/registration plugin, something to turn off toolbar, backend, something for handling emails, user-menu ...

I am fan of Decisions, not Options, but current "features" in WP are more legacy of old blog tool than a decision regarding to simplicity.

It's the Philosophy of WordPress to be easy, clean and simple.
80/20 rule should be followed more often.