> This has major "poll test" energy: a transparent attempt to deny people their rights with an intentional bureaucratic hurdle.

Or a way to reach people (and reduce fraud) when your mailbox is destroyed and you are in temporary housing. Same with people who rent. There was a case where the Supreme Court heard that requiring postage and stationary to mail a form to access government services was a poll tax and they rejected it. The courts may view email as the same way.

Protonmail does not use sms verification, but a lot of places block @protonmail.com without telling you. Happened to me with British Airways and stranded me in Europe until I bought another ticket. Never heard from BA, but another service told me it was because they offer a VPN service.

Within a significant bunch of friends/acquaintances, I'd be hard pressed to find more than 1 or 2 who know of protonmail.