This is only partially true. I have many GMail accounts (I often create a new one per each service where I create an account) and went through all of them a couple of months ago to make sure that they are not deleted. All I needed was a recovery email address (to which I luckily have access) and a brand new phone number (whatever number you have access to, does not have to be associated with the account in any way).

The part that is true though is that you're out of luck if you set a recovery phone and you no longer have access to it (same for recovery email). But even then I was offered a possibility to contact support to resolve it. And if someone is desperate they may try calling the new owner of the phone number and kindly ask for the code (you'll sound like a scammer, but hey, it's worth trying ;))