I appreciate I'm a bit late to the party here, but.. Does anyone have any type of explanation of why the UI in browsers for client certs are so user-unfriendly

I appreciate I'm a bit late to the party here, but.. Does anyone have any type of explanation of why the UI in browsers for client certs are so user-unfriendly? I would really like to use client certs more, but with things the way they are that's impossible right now. It's just too hard for a normal person to use them.