It’s not as good as, say, 1Password but it’s more likely to get used. Combine it with the browser or OS level password manager. It’s good enough for grandma, definitely better than “kitten4” that she’s currently using everywhere.
On a tangent, stereotyping this as “grandma” is a bit unfair. Most of my colleagues are college educated males in their 20s, some of them developers. And their passwords are rubbish, with no password manager, and no 2fa.