* SMM has been part of x86 for decades. The Secured Core requirements around SMM actually reduce its power.
* The claimed requirement to remove the third party UEFI CA certificate from 2022 Secured Core PCs is entirely unrelated to Pluton (it's required regardless of whether Pluton is enabled or not, and even whether the CPU has Pluton or not)
* Most of the description of Pluton is actually a description of a TPM. You don't need DICE for remote attestation. TPMs are already a hardware keystore.
* System firmware is already being updated via Windows Update. The discussion about Pluton and Windows Update is around Pluton getting firmware updates that way (the existing story around firmware updates for TPMs is largely not good)
* Existing TPM-based remote attestation already includes the secure boot state
The short version: everything that the article is worried about being enabled by Pluton is already possible, and has been for years.
But there's a meaningful point here. Remote attestation can certainly be used to restrict access to resources in ways that are incompatible with general purpose computing, or which reduce user choice. Remote attestation can also be used to give end users confidence that their machine is in a good state without constraining what they do with it. As a technology, remote attestation can be used in both good and bad ways. We do need to keep track of whether anyone is threatening to use it in bad ways and react appropriately.
(But tbh remote attestation as an attack on general purpose computing isn't the really scary thing about widespread remote attestation. Remote attestation ties back to the TPM's endorsement key, an immutable cryptographic key certified by the TPM vendor at manufacturing time. The straightforward implementation of allowing arbitrary remote sites to trigger remote attestation would tie all of these accesses back to a single piece of hardware, and would be a privacy nightmare.)
everything that the article is worried about being enabled by Pluton is already possible, and has been for years.
There's a HUGE difference between "possible" and "very easy to deploy". https://news.ycombinator.com/item?id=29859106
That means in three years, every supported PC will have TPM 2.0. Within ~1 year, assuming that Intel and AMD fulfill what they've implied in the launch announcement, every new PC will also come with Pluton.
That's a lot easier to deploy to compared to having some PCs with TPM, others without, some out-of-date on TPM 1.1, some with unpatched firmware (like the 2017 Infineon bug), so forth.
Now... some say, what about non-Windows systems, like macOS and Chrome? Think bigger for a second - Cisco (as an example) is in the Trusted Computing Group that designed a lot of this stuff, and Cisco Meraki is deployed in so many businesses for Wi-Fi security its incredible. All Cisco Meraki has to do (for example, maybe its not Cisco) is make a connection app that uses Pluton/TPM on Windows, Secure Enclave/T2 on macOS/iOS with Apple DeviceCheck, and SafetyNet on ChromeOS/Android. And you are all done - you've successfully made sure every new system is almost certainly untampered with. You've locked the door. For any system that can't be verified, no problems sending them to the IT Help Desk to be manually registered with a private key and sign a disclaimer.
It wasn't possible before, but five years from now, it will be much easier. Every Windows PC will be on the same page, and all major systems will have consistent assertion frameworks. Now, is Pluton wholly responsible? No. Windows 11 plays a role. Pluton just makes it broader and stronger, and Pluton also provides a long-term strengthening as eventually the TPM 2.0-only level will be able to be cut off for just Pluton.