S3 sleep is a solved problem and security issues around it are solved by Secure Boot and memory and disk encryption.
The issue is that firmware vendors disable S3 sleep in favor of s0ix/Modern Standby instead, which just puts hardware into low power states instead of stopping them entirely. This will inherently drain more power over time than just keeping memory powered in S3 sleep.
Modern Standby requires heavy integration with the OS to be power efficient. Turns out that takes a lot of reverse engineering because vendors will not release documentation or tune the kernel for their firmware.
Not just laptops but affects computers too. I have a brand-new Mini PC with Windows 11 and when you turn it "off" it continues to pull 6-10 watts. Not a lot but still over a year if you were to only used it minimally that's 52-83kwh or around $25-45/year at PG&E rates. Vendors are removing support for classic standby/hibernate so the only way to go to <1 watt is to pull the plug. It shouldn't be this way.
My thinking is that Microsoft is basically the most influential in that, as they badly want to do their "stuff" while the laptop is not in use. Their "stuff" requires network connectivity and seemingly they believe they can do updates, or any other "optimizations" when the laptop is in "modern sleep" mode.
I'm surprised this required implementing a whole new sleep mode. Since it seems to be mostly used for async background tasks, why not configure the RTC to wake the laptop every hour or so (I think every laptop in existence already supports suspend with timeout) and go back to suspend if no tasks need to be done?
The issue is that firmware vendors disable S3 sleep in favor of s0ix/Modern Standby instead, which just puts hardware into low power states instead of stopping them entirely. This will inherently drain more power over time than just keeping memory powered in S3 sleep.
Modern Standby requires heavy integration with the OS to be power efficient. Turns out that takes a lot of reverse engineering because vendors will not release documentation or tune the kernel for their firmware.