I wrote a whole SDK for using SGX, it's cool tech. But in theory on Apple platforms you can get a long way without it. iOS already offers this capability and it works OK.

macOS has a strong enough security architecture that something like Darkbloom would have at least some credibility if there was a way to remotely attest a Mac's boot sequence and TCC configuration combined with key-to-DR binding. The OS sandbox can keep apps properly separated if the kernel is correct and unhacked. And Apple's systems are full of mitigations and roadblocks to simple exploitation. Would it be as good as a consumer SGX enclave? Not architecturally, but the usability is higher.