They're resilient to spam, but often impossible to recover.
I had a spare SIM card that friends and family use when visiting from abroad. It's been unused for 90 days and has been deactivated. The number is lost, and irrecoverable. A friend had created a (second) Signal account with this number and can no longer log into new devices.
As a more mundane example: If I accidentally drop my phone into a river, the SIM is gone forever, and so is that line.
Sure, you can have a contract line which allows recovery. Depending on where you live, these can be several times more expensive than a regular pre-paid line.
You don't need a "contract" for recovery, just an account.
E.g. in the US, Mint Mobile is $15/mo. and is prepaid in the sense that you buy blocks of months at a time. But if you lose your SIM they'll still send you another one with the same phone number.
So no, if you lose your SIM you don't necessarily lose your number, even if it's prepaid. That only happens if you're buying your SIM as an "anonymous" one-off purchase, which is not what most people do these days. Not to mention the increasing prevalence of eSIMs.
"Often impossible"? Not my experience at all. Maybe it would be more problematic with prepaid SIMs, but why would a monthly billed account get deactivated?
You lose your SIM? You go to a branch, verify your identity, and get a fresh new SIM for your line. There's no more straightforward and surefire way to recover any other type of account as of today.
No. I believe that it's way easier to recover your phone number when you lose your SIM or change your phone (eSIM). When you lose your email password and the recovery code at the same time, your email is gone, forever. That's a huge difference, IMO.
Yeah, it may not work when you buy a prepaid SIM and decide not to use it for a long time, but for billed plans, it's impossible. I've been using the same cellphone number for the last 23 years. I'd got my phone stolen, I was able to reactivate my cell the same day with another phone.
Well nobody is a bit a overstatement when thousands if not millions of people actually do run their own or partial email stack. If you don't own your email it's just as bad as a phone number, but not worse.
In general emails don't just get removed and given out again if you don't interact with them for a few months. Phone numbers do usually after 6-12 months or even after 3 months for some providers.
You can prepay a domain for up to 10 years or more and always setup a email server when you need it so you essentially have full control, long term.
And don't get me started with possible SIM copy and stealing attacks. Things already pretty much solved with email and DMCA
I said "nobody does" because nobody can. It's a practical impossibility to run your own email today. It doesn't even matter if you have the necessary advanced technical skills. It's just not possible. https://cfenollosa.com/blog/after-self-hosting-my-email-for-...
As the owner of the same cell phone number for the last 23 years, proposing hosting your own email as an alternative to SIM cards that's available at every corner doesn't sound feasible to me at all. I don't even like cell operators, but that's just the way it is.
That's one anecdotal experience and simply not an ultimate turth.
I've had a email startup (sold meanwhile, but still running) and seen all these mentioned issues and know very well how painful this can be, but far from impossible. There is a market for clean IPs for company infrastructure, that's a thing still as well.
Probably I shouldn't say email is much better. But phone numbers definitely are a very weak decision for any kind of security.
