I don't think it's practical to not use a password manager anymore. There are too many data breaches to keep track of. A passwords manager lets you use randomized 50 character strings as passwords on different sites and keeps track of them.Would y’all say it’s safer to use the notes app on iPhone or is that a big target too
Use a password manager and make a password you can reconstruct or remember that's over 20 characters long and store that on an iPhone note. You can encrypt the note by locking it and you can get your iCloud data encrypted end to end now.
FYI if you lose your iCloud password and lose access to your phone that data is unrecoverable if you go that route. Apple basically hands you the key and washes their hands of it.