My shortlist, off the top of my head:

• Trying to solve screen tearing with Nvidia drivers.
• Trying to get LightDM to show me my god damned profile photo on login (still have not succeeded)
• Debugging a problem where my DE fails to come up on login unless I manually hop to TTY7 myself
• Endlessly forgetting which of the two or three different directories my .desktop files actually live in, and navigating the poorly-documented format for modifying them
• Fixing apps in my taskbar showing generic Wayland icons
• Trying to have any consistent success at all with Bluetooth
• Trying to figure out which fucking audio stack my distro actually uses so I can know for sure whether the magic incantation on StackExchange will fail because it’s for the wrong stack or fail because it’s the correct stack and the stack is garbage
• python2 and python3 symlink hell
• Faffing around with WINE settings

I thrive in the pain. But yes, there is plenty of pain.