Thats exactly why I copy and save every 2fa QR Code in my KeePass database, along with backup codes. Phone changed? No worries, install Google Auth, rescan those QRs, and voila, your 2fa system is back and running !! :)
Most 2FA services that allow authenticators offer recovery codes. I keep the recovery code saved in my password manager, and if I ever lost my phone I use that to log into the site and then get a new QR code.
Yes, that's also a way, but why not save the QR code first time you see it, instead of loosing it, resetting with recovery code, and then again getting a new one? Recovery codes are fine, and should be kept safe and such, but also the Original QR code can also be saved and screenshot. That way, phone lost? open database, load QR code, scan in new phone.
