I understand that some data is considered cached and shouldn’t be backed up. But Android already allows that.
> Auto Backup excludes files in directories returned by getCacheDir(), getCodeCacheDir(), and getNoBackupFilesDir(). The files saved in these locations are needed only temporarily and are intentionally excluded from backup operations.
Overall though, this has been a solved problem since 2010 on iOS. True you only get 5GB of iCloud storage by default. But you can pay for more or use iTunes for local backup