This whole Wayland hate makes it seem like something is severely broken, where in fact it's more of a storm in a teacup.
A: Google "linux hibernate", read an article from ArchLinux wiki and several forum posts, decide which one to follow (because they'll talk about several conflicting approaches and some of them won't work for you), find out the UUID of your swap partition, add the UUID to the correct place in /boot/grub/grub.cfg (you should have an editor installed and know what "sudo" is), reboot, try running "sudo systemctl hibernate" and see if it works. Easy peasy!!! Oh, and locations of some files will be different from what you've Googled, depending on what distro you're using, so you'll have to hunt them down. Good luck!
(True story from a few weeks ago.)
(No, didn't have time to figure out how I can enable hibernation from the "Start menu" - that's for another time...)
Yeah... the Linux Desktop is really doing fine, I can totally see it.
Most software nowadays have their own session management, so their session is preserved both across software restarts and reboots without OS hibernation.
Also, one of the main reasons to reboot your computer nowadays is to reload updated libraries, which hibernation skips.
And with SSDs, most computers take at most a dozen seconds to boot.
Hibernation is hacky on Linux because hibernation is hacky, and it doesn't provide much value when you can already boot your machine in a couple of seconds and get all of programs back in their previous session, without the hackiness.
Uh, no! Both windows and AFAIK macos (although they call it standby, not 100% sure they still do it on the Arms) use hibernate as a deeper sleep states for machines that have been sleeping for some length of time.
So, use case, unplug a laptop computer from dock at work on Friday close the lid, throw it in the bag, return on Monday, or maybe two weeks later after a holiday/PTO, open the lid, and it's precisely where it was on the Friday when it was undocked. (On topic bonus is that using Xorg all the windows move to their previous locations when the machine is plugged into the dock, while using a nvidia optimus setup, just positioning windows where they were isn't something wayland seems to be able to do consistently in my experience).
I don't think I've found an S2idle machine that can achieve resuming two days later in linux, and I've got a pile of them. Most of them will burn a percent or two an a hour. S3 standby machines (real ones not the ones faking it) can usually do a few days but they also have issues with the week long timeframes.
This is solved with hibernate, which is configurable in linux, and the machine i woke to type this on has been in hibernate is at 99% battery.
One of the nice things about KDE is that the system settings panel has reasonable configuration options for hybrid sleep/hibernate. Like on windows it shows the option to "While asleep, hibernate after a period of inactivity" or just use hybrid sleep (which writes a hibernate image to disk before sleeping, so if there is a power loss, it can still resume, which is useful on desktops that are sleeping).
So, no, some distro's (ex: fedora) removed the option during install and decided that compressing swap to ram was a better plan because they think people have slow EMMC storage and limited RAM, rather than fast NVMe disks and laptops with 32+G of ram and they are still getting regular issues with OOM/etc and now its an extra step if you actually want to have a chance of opening the lid on a laptop and picking up where you left off.
So, no, hibernate is not obsolete just because there is a subset of users who think their narrow use case means everyone uses computers like them. Nor is it any more hacky than any other suspend/idle mode in linux.
And no, session management isn't the same, and most apps don't know what to do (particular on linux) when the machine needs to shutdown due to low battery. And plenty of applications don't consider part of their data to be persistent. Scroll back buffers in the terminal apps I use for example.
I really appreciate distros that add an ext4 label to your root partition, so that you can just add resume=LABEL=Root to your kernel cmdline and get hibernation ready, nothing else needed. I do a custom arch install and make sure to do that. You can do it later from a live usb as well, iirc, e2label is the command.
I like that phrase though "storm in a teacup"
It is.