This kind of thing has a history, eg this was on top of the TPM platform: https://web.archive.org/web/20060822043633/http://www.hpl.hp...
I wonder what's different this time.
Confidential computing lets you reduce your TCB to the software running in your guest, be that a full OS like Linux or maybe some unikernel type thing, and the hardware itself. The intent is that a malicious host could not read or modify guest state, though of course they could simply refuse to schedule it.
This could be used for DRM or nefarious purposes, but that’s not the point.
Obviously this is no more secure than the underlying hardware. All the attacks against SGX, for example, will still apply unless they are fixed.