Comment by j1elo

Correction, in case you're interested: Whatsapp does (and has always done) allow local file backups. I know because they are just there on the storage:

  Android/media/com.whatsapp/WhatsApp/Backups/

I also know because for many years I was VERY cloud-averse so for several iterations of smartphone purchases I did migrate my chat backups between phones (plain copy-paste of files with a computer) without issues.