People should do this, and people should stop telling other people it's bad security to do this. And then people should stop using password managers.
The idea that the sticky note is bad is hilariously old school, and the result has been everyone putting their passwords in cloud-stored apps instead, which is 10,000% worse than a sticky note.
Remember: If it's on the Internet, your potential attacker is "every human on earth". If it's on a sticky note, your potential attacker is "everyone who can get access to the physical place you keep it". The former will always be an increasing number of billions of Internet users. The latter can be reduced to one or two if you store your sticky note somewhere very secure, like a safe or security deposit box.
Also, for added security... just lie on your sticky note. It doesn't have to be a high entropy lie to befuddle people.