I am on my phone and lazy so excuse missing sources. But afaik a lot of malware targets password managers. Dont forget that some of these also are really really bad and easy targets. some bigger ones may be good, but still tend to fail from time to time.

a unique password for every site is defintly better, but not if these passwords are saved anywhere.

My sheme, which only exists in my head, imo provides therefore more safety.

honestly i am just paranoid, but the way some users use password managers scares me.