Email and SMS are not reasonable and both have an extraordinary number of flaws.
I’d buy that there are too many different confusing ways to recover from this situation, but not that it’s impossible
Fun fact: Google can decide to reject these. Lose access to the original device, try to rely on recovery codes to login with known current password on family member’s device… nope!
When you upgrade your phone perhaps keep your old one in a safe and charge it and login to Gmail monthly or something?
I’m also quite certain the codes could work instantly with no trouble in some circumstances. Now know it’s risky though. And I’m sure it’s a security measure based on real, deeply painful and costly instances of unauthorized access. Just don’t know what we’re exactly supposed to do…