Password manager-less life with notebooks and reused passwords is life in the stone age. If you or anyone you know isn't using one, get on bitwarden.
Everyone knows why password manageras are absolutely essential, but here's an often neglected perk: I can list every site I ever signed up to. Wanna delete some old accounts?
"Did you sign up to X yet?"
Simples.
+1 for BitWarden. Tried LastPass, 1Password, but ultimately settled on BitWarden because of how well it integrates with multiple platforms e.g. MacOS. It also allows sharing TOTP which is not a great idea in general but is sometimes required - e.g. my kids’ school requires it but only allows one “parent” account that my wife and I share.
Just FYI, 1Password can do the same (Share TOTP and integrate with all platforms). Not saying it’s better, just saying they contains the same functionality.
I helped a friend set up an Instagram account for some project she was doing and discovered that her password system is a notebook. And do you know what? I didn't say anything. It's probably safer for her - it's shelved with other books, it doesn't have "passwords" on the cover and having showed her how to post on Instagram, I know that teaching her how to use Bitwarden (my manager of choice) is out of the question. She's younger than me, she's bright enough, but her life is mostly analog.