Restoring memory is useful if, when you resume an agent VM, you want the apps to be in the exact state when they were suspended.

But for most things, I find resuming with memory is more trouble than it's worth. If you always resume from memory, you lose the ability to control the state of a VM. It's much easier to define which services should run than to define which active RAM state should be purged

Similar to why "did you try turning it on and off again?" is good for system reliability.