I have no idea what the pros and cons are and certainly can’t speak for why. However, I think the existence of the Advanced Protection Program is definitely acknowledgment that the SMS backup is not secure enough for everyone.
The thing is, not long ago I had no issue recovering my account if it got compromised. I think attackers today have gotten better at finding ways to beat the system. One thing I’ve seen, albeit I don’t know if it works on Google accounts, is enabling high security after stealing an account, effectively making recovery very hard.
Though, I can’t really speculate on if that’s what’s going on here.
The thing is, not long ago I had no issue recovering my account if it got compromised. I think attackers today have gotten better at finding ways to beat the system. One thing I’ve seen, albeit I don’t know if it works on Google accounts, is enabling high security after stealing an account, effectively making recovery very hard.
Though, I can’t really speculate on if that’s what’s going on here.