Semi-locked out of my account

Hi all, hoping for some help.

Basically my issue is: I have purchased a new iPhone 16e and upon trying to set it up, when it has requested me to sign into my Apple ID, the verification code for two-step verification has not come through to my trusted device (goes without saying I am signed in and should be able to receive the code). Both devices have the most up-to-date iOS/iPadOS, and this problem has been occurring on my account for at least 5 years now. I do not have my Recovery Key available, as I've had this account for far more than 10 years and it has gone missing.

I have had three phone calls with Apple Support and have not been able to find a solution. As it stands, I am locked out of my account on my new phone, which is obviously not ideal.

Has anyone had this issue before?

If nothing can be done, then how simple would it be for me to set up a new account and then transfer everything (including my phone number) to a new account?

TIA