In the article. It says (paraphrasing): Time Machine goes wrong (over time!), Spotlight doesn't index tags right (requires relaunching Finder), Finder sometimes hangs when using Spotlight (requires relaunching Finder), folders sometimes won't update to show new files (requires relaunching Finder), using Quick Look on a video makes airpods glitch, and switching by cmd+tab to a fullscreen window doesn't give it keyboard focus.