Not at all in reality. You lose your phone you simply answer two security questions and provide the number for your new phone. That's the reality of 2FA using a phone, but your solution is a fantasy: a perfect phone auth system.
How much you would you pay me for access to my voter account and my ONE vote? Not enough to make me want to risk 10 and 10, because allowing unauthorized access to my account would be classified as national security violation, meaning Federal crime. The penalties are part of the package, too.
Just like the OP you propose detection and penalties. There isn't any detection or penalties now and there won't be unless you figure out to detect mass registration fraud.
....custom latex mask to impersonate you at the government office...
Fraudulent registrations are encourage by that office. They want more fraud. They don't care who you are, illegal, duplicate, desd, whatever, it doesn't matter to them.
What you seem to be pushing is internet voting verified by a phone text message. Our adversaries will port millions of numbers and fail to port a large percentage of those. For those they fail to port they will attack with apps that intercept your SMS and send it to them. Then you have to be faster to the voting site than them. Barring that they will use false attempts and lock your accountm then masquarade (online as usual) and get a new one-time password from themselves. Or they will simply lock everyone's account and prevent voting by anyone.
You seem to have a problem with reading comprehension. The rules about making a personal appearance and providing ID to register, reset or renew your online account are part of the package.
It’s my idea, so my rules apply. If you want to apply your own rules, then it’s your system and not mine.
Your attack scenarios are fantastic and would be NOTICED. If online voting was somehow disabled by a system-wide attack, you would have to schlep yourself down to the polling station and vote on paper, oh the horror.