First sentence of your second link : "If you’re a ProtonMail free user, you can export emails individually and save them locally on your device".

Good luck when you have 3000 emails and you are physically disabled.

In other words, signing in and using the service is "free", but you must pay to quit it or move to another provider.

There are also many other data than just emails : contact list, your private keys, the folders/tags you used, and all other personal data that Protomail may have about you.

Facebook and Google allow you to download a single zip of _all_ your data, at any time you wish, _for free_. They do it because it is required by the _law_, not because they are being nice.

So, yep. I would send a big warning to anyone who wants to try Protonmail, because Protonmail's terms of service uses dark pattern in that regard, and probably illegal in EU or California.