Your "you're the 18th century person" comment is needlessly insulting as well, especially given that what you've commented is basically irrelevant.
No, they're true, which is what makes your reaction so interesting. You might more successfully argue that this (other people knowing your password) is a trade worth making, but then as I explained you don't need to make this trade at all, so the value you're getting by accepting the current practice is zero.
The thing they're "selling" on that site (promoting) is a distributed system where only you can decrypt your own data. There are a bunch of situations where that's not applicable, but even in those situations the other party doesn't need to know your password - so why do most sites do this?
Mostly laziness.
There are literally zero situations in which I would get actual real-world better security from a site not having my password, given (a) that they're properly hashing it, and (b) the password isn't used to encrypt any personal data.
Claiming that sites doing those two things have "fake security" is the kind of bullshit that smells like a marketing scam, which is exactly what makes me suspect they're selling something. (Again, without having any further evidence in that regard.)
Even if a site is using a password to encrypt personal data (basically the ProtonMail scenario), I still have to trust the site itself not to steal my password, so additional security provided in that scenario is marginal at best.
The claims are akin to "we use only 512 bit AES, sites with only 256 bit keys have FAKE SECURITY". It's at best extremely misleading, and hard to imagine that it's not some cynical FUD marketing technique.
https://krebsonsecurity.com/2019/03/facebook-stored-hundreds...
Claims that this means Facebook weren't "really" properly hashing it or are otherwise an exception constitute a No True Scotsman argument.
It is _definitively_ less safe to do what is commonly done today. There is no _practical_ benefit and there are plenty of things that can go wrong.
Everything we do is Open Source.
Get your facts straight.
Yes, the NSA really did use backdoor access to servers to spy on millions of people.
Snowden.
So use better security, like real cryptography.