However, Google won't let me log into the old account without veryfing access to my old phone number, which I no longer have since I moved to different country for uni.

The worst part is that I do know the correct password for my old account (it has been stored in my password manager for years) and I also have access to the recovery email set for that account.

This is an account with years of emails exchanged with my parents that I would love to archive, but I can't and I find that to be highly dissapointing.