Disagree. Having your passwords written down like that is arguably quite sensible.
You have longer, more varied passwords that dont follow a pattern, and are held offline rather than in an online Vault like Lastpass or Google. Its only weakness is to someone physically sat at your desk, (or who steals the notebook), but what is the probability of that?
Slim to naff all, i would hazard a guess, especially if the notebook doesnt have “PASSWORDS!” written on the front of it.
I’m not going to get into the pros and cons of password managers, been done, but I will point out that every time I’ve seen someone with a hand written book/list of passwords they are always mydog, mydog1, mydog2, etc etc and never the randomly generated ones you speak of!