I have tried 3 different Macs with different versions of macOS prior to looking for a workaround, and everywhere the result is the same: old photos are not downloaded automatically from iCloud, and there is no button to start this process - for this exact reason.
Want to prove me wrong? Create a new macOS user and open Photos with your iCloud. It will be empty until you start copying photos from your phone. It will take much less time than arguing here.
I have tried 3 different Macs with different versions of macOS prior to looking for a workaround, and everywhere the result is the same: old photos are not downloaded automatically from iCloud, and there is no button to start this process - for this exact reason.
Want to prove me wrong? Create a new macOS user and open Photos with your iCloud. It will be empty until you start copying photos from your phone. It will take much less time than arguing here.