I've been fortunate to be paid by Google to hide user data from Google since 2016. Not many companies would shell out anything for this sort of privacy feature.
As for the Oak stack, they win the race. It is the only stack that currently provides full hardware attestation covering 100% of the code running in the enclave, and 100% of it is open-source. There are other good efforts, such as CoCo containers with their Key Broker, but so far they only cover the initial boot firmware, not the full set of software running inside the enclave.
It’s really apples and oranges, Oak is about being able to execute code without side effects, even when it’s running in an environment you don’t provide. If it gets extended to the phone you can snark about ads, but really it would only be able to address whether any data associated with your viewing an ads escapes to a third party. So it would largely make ads be more like a billboard vs the way they work today. But that’s speculation, Oak isn’t trying to make the world safe from advertisers, it’s trying to make your data safe from being used in ways you didn’t permit, even when it’s being operated on in an environment you didn’t provide.
