Modern Standby enables much faster return from Standby. You open the lid of your device and it's there. That's not the case with S3. I find it adds a lot of convenience.
My 10 year old Thinkpad with S3 wakes up in the time it takes to open the lid, with almost as much battery as it had when I put it to sleep days ago.
My shiny new work laptop without S3 wakes up in the same time, and then says "Battery critically low, shutting down."
This is not a convenience, it's insubordination. I told it to sleep, and it didn't.
But you know what's really insane? When the new work laptop is just sitting there with the screen locked and I walk up and hit a key, it takes longer to just display the password box than the 10 year old Thinkpad takes to wake up from S3 and display the password box. (Ok, it's an unfair comparison, Windows vs Linux, but still...)
How is this the case? Suspend to/from RAM on Linux wakes up in less than a second in my experience. Which makes sense, because everything is still in RAM and systemd doesn't need to do a bunch of work to get everything back online. Maybe Windows has a weird implementation of S3?
Funny, one of the reason why I started heavily using S4 rather than S3 was because with SSDs the time to restart from swap was so fast that it was barely more an inconvenience.
My shiny new work laptop without S3 wakes up in the same time, and then says "Battery critically low, shutting down."
This is not a convenience, it's insubordination. I told it to sleep, and it didn't.
But you know what's really insane? When the new work laptop is just sitting there with the screen locked and I walk up and hit a key, it takes longer to just display the password box than the 10 year old Thinkpad takes to wake up from S3 and display the password box. (Ok, it's an unfair comparison, Windows vs Linux, but still...)