Don't. Sharing a Netflix account with your family is easy. Send it in the whatsapp group if you need to change the password or something -- how often are you going to do that in your life? Not enough to justify handing over all of your password to a 3rd party and paying them money for it.
Anything more important than a Netflix account you don't share at all. If they need access, just call them.
> how often are you going to do that in your life?
Small startups use password sharing tools to share passwords with new employees (think db passwords or other saas accounts). This happens at least a once per month in a 10 person organization.
That's the intended use case IMO and it absolutely makes sense. I used to share passwords in Slack before and that made me uneasy, the company investing in a password sharing SaaS absolutely made sense. However, I do not manage 100+ people at home and thus have no need of one.
Anything more important than a Netflix account you don't share at all. If they need access, just call them.