Long enough that it’d be hard to rule diet as your cause of death. Your biggest consequences would be low energy and a weakened immune system. Not a great place to be, but you’re not gonna be so weak that you fall over to a stiff wind. It would take an untreated illness like the flu or pneumonia to actually kill you.
Necessary but evil. My workplace had a million headaches implementing an email-based 2fa system. So many automatic services blocking our emails, so many people who are tech illiterate who cannot understand 2fa, and all of their calls got sent to me and my team despite none of us having technical support experience. However, it has massively increased the security of our site, while allowing us to finally implement a way for people to unlock their own accounts if they do have too many unsuccessful login attempts. The juice is worth the squeeze.