With respect to passwords, biometrics and password managers (or better yet, public key infrastructure) is the solution. Not privacy booths. If I had my way, apps wouldn't let users pick their own passwords: they'd email users 30+ character generated passwords that they couldn't possibly memorize and thus force people to use password managers.

Unfortunately, enforcing strong passwords drastically discourages new user signups. I remember when the security team enforced stricter password policies at Dropbox new signups dropped by a factor of 10 (by "stricter" I don't just mean length + special chars, they experimented with banning all of the 100K most common passwords). It just isn't economically sustainable to enforce strong passwords.

perhaps if you have a weak password, your service level or class is constrained.