Probing a live chip for 30k - https://zeptobars.com/en/
Probably cheaper side channel attacks, too. To some extent this depends on the software running under SGX.
how this will help if the encryption/decryption happens inside the chip?
It is a viable additional client protection, especially against remote malware, software-only tampering (unless there are implementation bugs or backdoors), but not a viable server trust substitute.