Q: Optimised photos backup workflow..?

So....a while ago I optimised all the photos on my iMac and purchased plenty of iCloud storage to hold my photo library for some time. All great so far...saved plenty of space on my hdd and all the photos pop up on all devices. The library now contains around 21000 photos and videos ranging all the way back from 2002.

My question is....the photos taken with my phone lately have been going straight to iCloud without being backed up in full resolution to any other storage. How do you manage this..?

Apple says on their iCloud page that photos should also be backed up locally in case iCloud fails I suppose.

But since on my mac I now only have the optimised versions....what workflow do you use to backup your photos taken with a connected iOS device...?

//Fred