1Password I think is the most user friendly. Granted I haven't tried BitWarden, but I got my dad using 1Password and he manages ok. My mom never did quite figure it out though.
Honestly, consider something like this: https://www.amazon.com/Internet-Password-Logbook-Cognac-Leatherette/dp/1631061941
Hear me out. I know these are the butt end of every joke people can make. However, the same people committing cyber crime and breaking into bank accounts are not the same ones that will rob a house and go looking for that book. The more important part is getting them into good habits around using unique passwords/not reusing passwords, using 2FA, and generating complex passwords (I love this: https://makemeapassword.ligos.net/generate/readablepassphrase). These practices are all more important than specifically where the password's are stored (as long as they aren't stored in pastebin or something). I feel like the biggest risk with a physical book is that if your house burns down or something, there is no backup/redundancy.