I really wouldn't say Cage gets murdered by the top-tier characters. The characters who are most widely contended as S-tier right now are Kung Lao, Raiden, Kabal and Reptile, all of whom he has an answer for. Cage vs. Kung Lao is 5-5, I know that one from experience. Cage vs. Raiden doesn't seem like it'd be too bad, since Raiden can't even teleport in without the risk of getting shut down and his B3 1 2 will just eat an EX shadow kick. Cage vs. Reptile can't be any worse than 6-4 Reptile, and while I've really never seen/played Cage vs. Kabal, Kabal's IAF could easily be shut down by the EX shadow kick with almost zero margin of error (which is a pretty big deal, because most of the time, you run the risk of mistiming it/guessing wrong and eating a full punish if it's blocked).
Cage is a very limited character, but he's so good at what he does that I still consider him S tier. That said, I also consider Sonya as a potential S tier character, but I've yet to SEE a good enough Sonya. She sounds great on paper, but I'll have to see what she can really do in practice before I make a conclusion.