If something is weak, it is Proton’s knowledge of password strength. For example, they call a 16-character password without special characters “weak,” which has around 95 bits of entropy, so this doesn’t make sense. They also overemphasize the role of special characters in passwords, as just increasing the password length by a single character would add more entropy than enabling special characters. Furthermore, many of Proton’s articles regarding password strength contain a lot of misinformation. This one talking about password entropy might be their worst yet. You cannot seriously claim that a single word, “Bankruptcies,” has 68.4 bits of entropy, which also isn’t the only inaccurate claim that the article makes.

You are right that Proton is currently self-funded by its paying customers, but to be accurate, they have actually taken VC money before.

I don’t see an option for a 24-month plan.