Delays and Sluggishness
For the 30+ years I've been using Adobe Illustrator, I don't think I have every really been bothered by the app or an update until last year. Now when you open AI, make a new file, or try to drag content around on a canvas or move the page around using the hand tool, the app is very lethargic and jerky. It is as if it is validating all actions by an online verification before any action is done. This really makes using the app frustratingly slow.