No. Anyone near you or with access to your place can see it. And most people know of the tricks.
Also you can’t encrypt it and most of all you can’t really generate as strong passwords as those generated by password managers, meaning I don’t even need the paper to try and crack your password
It’s still nowhere near as secure and convenient as using an appropriate tool. You will either have one that is easy to decipher and remember or one that is hard to decipher and remember. And you have to do it every time but at that point you might aswell just remember one password/passphrase and use it for your password manager, defeating the whole point.
Also bare in mind convenience is important in security, if a measure is very inconvenient you will eventually just bypass it on your own cause you can’t be arsed.