There's an old saying... if it ain't broke, don't fix it.
Yahoo used to be so user friendly and now it's confusing and complicated and messy and it's just awful to use. When I look at my in-box, it has too many descriptions and the email itself is totally confusing - I can't tell who sent and who received and which one is the final one. I'll click on something and the whole message will transform into something that makes no sense.
Sent messages don't get sent but go to drafts and I have to go into drafts to send but then I don't know if I've just sent it twice. I don't want to change but if they don't make it easier to use, I probably will switch.