Linux has no trouble with hibernate/suspend, at least on my machine. It's just that I prefer to start from a clean state each day and don't want to be bothered with yesterday's clutter.

I also save downloads and small 'run once' experiments to /tmp, so booting the notebook is a good way to clean everything up.

To add another bullet to the reasons for reboot listed in the siblings, I prefer to poweroff in the evening because my disk is encrypted and I don't want the key lingering around in RAM when I don't need it. /me puts on more tinfoil

What's wrong with hibernating and suspending? It's been two months since I last rebooted my Linux laptop, I typically only do it when upgrading the kernel. I agree it would be nice to keep session state after a reboot, but it's a very minor annoyance. Some window managers such as i3, do at least let one persist window configurations.

Nothing, other than that it 1) may not work on all hardware and 2) slightly increases battery drain.

Suspend (to disk) can be slow on some hardware -- moreso than rebooting. Though it preserves state.

Clearing user state is one of the reasons I prefer reboots - it helps keep my desktop clean and tidy. I cannot imagine the mess that would arise if my session lived months. I use shutdown as a shortcut for "close all application I don't use right now"

If that's your preference, great.

But again the point is that presuming goals/preferences, or attributing them to all others (and no, OP didn't do that) scales poorly.

As with most workflow preferences, the details are highly internalised.