That's how they used to work! Some used peer-to-peer networking, others had one of the players host. Some still let you do this but don't always have networking that "just works".

> the subsystem is "responsible for creating, monitoring and maintaining the security environment" and "its functions include managing the boot process, initializing various security related mechanisms, and monitoring the system for any type of activity or events and implementing an appropriate response".

It implements TPM or something similar. It is used in the boot process for a secure boot chain. And the last generic point is probably just that it implements the hardware random number generator for the CPU, which Secure Enclave also does (in a different way).

I could worry about Secure Enclave being used as a backdoor and being a security concern, too. Doesn't mean it actually is!

Which benefits Apple because it gets rid of competition on their platforms.

> Apple’s incentives align with those of user privacy and security, and so I am willing to give them a lot of leeway

At the cost of your freedom. Sure, it's not that bad now, but I'd be worried about the future of macOS because it's the least restrictive Apple platform right now.

AMD PSP is little more than an embedded TPM. The capabilities are significantly different vs. Intel ME.

IMO it's pretty arbitrary. I wouldn't expect to run software on an appliance, even if the underlying hardware is commodity. And an appliance is something that performs a specific task (fridge, car, etc.). There are gray area cases though when an appliance does more than its basic function (smart fridge, car infotainment).

Just look at Apple's stance on third-party web browsers to see what I'm talking about. There are browsers which respect user privacy, have good security, etc. but Apple uses the same excuse there: only Apple can be trusted to do it right.

> But barring that, having them volunteer to be responsible stewards—and prevent others from acting badly here—is potentially one of the best alternatives.

This is the part that bugs me. Reputations are earned. Ask yourself: would Apple allow another entity to deploy their AI assistant on iOS if they respect user privacy at least as well as Apple? I doubt it! Apple is not doing this as a kindness to its customers - it directly benefits Apple as an excuse to lock competitors out of their platform.

How can you know whether Apple would actually respect your privacy or not? If it's on-device you can audit it, but how can you prove their cloud is actually respecting your privacy?

If you have an answer to this then why can't third-parties also do the same?

I haven't read all the details but wouldn't SKG pin this responsibility on the game developer/publisher instead? Meaning you can't rely on a third-party to release a solution because they might not do it.

> Or publishers that use Valve servers for matchmaking can just replace them.

Steamworks makes a lot of systems available to developers (DLC, microtransactions, inventory, server browser, lobbies, authentication, networking/datagram relay, P2P networking, input binding, UGC/workshop, cloud sync, ...). It could take a long time to replace it all, especially if your game only shipped on Steam. And when you're done you get to worry about how you ship that update to players, because you might not be able to do it via Steam!