iCloud drive app Sync

Hello

analyzing data traffic from my Intel MacBook Pro with Sonoma 14.5, i found a large amount of data sync locally each days, but not directly derived from documents or downloads folders updates in others Apple devices connected with same Id Apple (one iPad and one iPhone). So i try to investigate and i found that whatsapp make automatic backup on iCloud and sync start also to Mac.

I'm sure this behaviour it's "by design" of iCloud and it is correct in almost all situations with documents or files but i think also that that Apple cannot define the type of data that apps can put into iCloud space.

Also the amount of data transferred depends to the optimization of the data store of the app. So if the backup of whatsapp make yesterday a 5.1GB unique file data, today, regardless of whether total data increased or decreased, the backup will make another backup unique file. No incremental or differential mode can take place so each day my MacBook download another 5GB file each time.

I doesn't seem possible to disable local sync on MacBook of folders of Apps in iPhone (App that use iCloud for backup or other data) and leave it enabled from iPhone to i Cloud.

In conclusion I believe that synchronization brings a large amount of data locally, most likely useless.

Do you think everyone is wrong or is there truth in what I say?

Thanks

Michele from Italy