These attacks on SGX are some of the most advanced attacks on any TEE ever. The crappy ARM smartphone vendor TEEs regularly fall apart from mere C bounds issues.
You're making an apple-to-oranges comparison between TEEs and SGX. The attacks on SGX here are on the processor/model of SGX itself. Buffer overflows are bugs in the applets that run inside the TEE. SGX applications can and do have similar bugs. Here's a random paper I found, there are many more: https://arxiv.org/pdf/2110.06657.pdf
Distinction without a difference, as far as the secrets are concerned. It means your claim "this is why you can't watch 4k on desktop" is dead and done.