I understand the fear of the bridge being burned down. I also see how that would make Proton like WhatsApp, which has its own protocol and locks its users in. Would it be inaccurate to say that your fear is that Proton pulls an “Embrace, Extend, Extinguish” move?

In any case, it’s worthwhile looking at your claims. You mention that Proton is “actively trying to turn open protocols into more closed stuff”.

• Why can I use PGP as the encryption protocol in Proton Mail? Is that a closed protocol?
• Why could I download an archive of all of my emails last December both through IMAP and through MBOX? Are those two “closed stuff”? In fact, I could’ve downloaded my archive as EML; is that a closed protocol?
• Why could I download a copy of my contacts as VCF? Is that a closed protocol?
• Why can I export my Proton Pass passwords as JSON or CSV? Are those closed protocols?
• Is it really tenable to argue that Proton is pulling an “Embrace, Extend, Extinguish” move when they support PGP, IMAP, SMTP, MBOX, EML, VCF, JSON, and CSV?

You could argue that it’s simply a matter of time until they pull the rug and close their protocols. Let’s elide the whole discussion regarding the probability of the rug pull happening and instead focus on the present reality: as of December 2024, I could download an archive of everything I have on Proton without a hitch. They do not have the whole Meta thing of “Please give us four working days for us to create an archive of your data”. At least that wasn’t my experience. I could download an archive quickly.

• If users have the capability of downloading open protocol archives of everything they have on Proton, are they really stopping them from going elsewhere?

I understand your concerns of vendor lock-in. The fear is that it could avoid people leaving the service in the future. However, do you know that I use a generic email client that, through IMAP, contains a Proton account?