How to download 60,000 photos and videos from iCloud

Having relied heavily on the 2TB iCloud storage, the Photos library has finally ballooned to take up 1.4 TB of the storage. I'm looking to delete large number of them to free up storage on iCloud, but wanted to first download the whole library (around 60k photos and videos).

I have not found an easy way to do this, and have meticulously downloading media month-by-month. It's painstakingly slow, and Photos app crashes from time to time.

Just curious if anyone may have similar experience / solution to locally backup all the photos & videos from iCloud?