What are the benefits for turning on a recovery key for my Apple ID VS using account recovery when I lose access to my trusted devices or phone numbers, for example if your phone number gets changed?

What are the benefits for turning on a recovery key for my Apple ID VS using account recovery when I lose access to my trusted devices or phone numbers, for example if your phone number gets changed?

I have read the response to this question and I am really confused. I have researched this issue as well and NO where does it say that in order to use the recovery key code, you must have a trusted device. Every where on apples support page you read the following....

I have set up the recovery key code according to these directions, and now with over 20 calls to apple support, they say you must have a trusted device, but that is not what the website states. I have lost over 8 years of picture/documents/I cannot even get to my email. I reason I had to change numbers and email addresses , it was due to hackers gaining access into my finical accounts. I thought I was safe to gain access to that old account because of the directions that are posted on Apple's site.

SO now what? I know there must be something they can do, because I have the correct login in and password along with the key code!!!!!!!!!!!!!!

Please someone help me get my history back, it really makes me very upset when I think about all my information just being thrown away by no fault of my own.

Please advise