Stop leaving your unlocked computers unattended in semi-public areas. I'm not going to be "that guy" but you're asking for something dumb to happen.

Counter hot take: laptop manufacturers should set lockouts to be a short window by default & locking should be a one-button press by default to make it easier for users

Even fancier would be having different lockout timers when connected to networks deemed public vs private — that way it isn’t too annoyingly short before lockout if you’re at home & your only threat model is your cat walking over your laptop keyboard while you pee