Actually to answer your last question in the details. I believe it is achievable, even to some extent those with a receding chin. I notice that people close to me and myself included facial structure seems different according to weight lose and gain. There are also facial exercises that tone muscles in your face. Though after some experimentation I gave up on these as time wasters and overall silly.
@Jeruba is right though. People have different views of attractive. Fortunately for us all.
Also like @CWOTUS observed inner beauty is overall more important then the physical.
Still I have been known to be jealous of people for silly reasons and observing the silliness of them doesn’t entirely change my outlook, though it does help me modify them.
On the other hand maybe pointing out the extreme chin: Jay Leno, Bruce Campbell, Peter Griffin, American Dad father, and who was that other person….. maybe can put it all into perspective for us.