When my devices - mostly ThinkPads of different vintage running Debian plus a 27" iMac running the same - sleep they don't wake up until I want them to so yes, "Linux" is better in this regard. If your device wakes up when it should sleep I'd check if Wake-on-Lan is enabled.
It is now though. I agree that 5 years ago it wasn't ideal, but now the hardware support linux way better than it used to do, and on my dual-boot, i have 1/3rd more battery life with linux when i'm using it.
For the "never really idle" part, i've found a script on github that deactivate and uninstall most of the bloatware windows come with, and it's now way better, so i cannot judge.
I find hibernation to be the best approach. Zero battery drain, my laptop boots in 5 seconds (or negligible time to be concerned about). Just set it up to hibernate when the lid is closed.