Time machine back up files - can it be transferred?

Sorry, but Apple does not provide a means to transfer a TM backup from one APFS-formatted drive to another. In theory, it may be doable via a low level duplication, but it looks like VikingOSX has already tried, and was unsuccessful. The reason is the way TM stores TM snapshots.

I have not found any means via several approaches to transfer TM backups on an APFS drive to a larger, newly formatted APFS drive. Not via Finder, Disk Utility, SuperDuper!, rsync, ditto, or other method.

Apple used to support transferring TM backups from one device to another. They don't any more.

For reference here is the (archived) Support document: Transfer Time Machine backups from one backup disk to another (archived). That method (using the Finder) was incredibly slow, so I always preferred using Disk Utility Restore which took only a few hours at most. Unfortunately not even that works any more.

You can if the old TM drive was also APFS. Better to just start a new drive and keep the old one if really needed in the future.

You could be right. The last time I did this was with the HFS format and it worked but was a slow process.