I think I’d rather use the existing feature of sharing iCloud links for 30 days.
Advantages over this new shared library:
- I’m not using up
my iCloud storage with photos/videos my friends decide to share (assuming I am the “host”)
- I can have different groups of friends/family to share with, with more than just 5 other people
See
https://support.apple.com/en-gb/HT209035.
The new shared library feature does have some advantages, like it can be kept around indefinitely for the members to view. But the shared iCloud links feature gives them 30 days to download the images they want to their own libraries.
And the new shared library feature will only use up iCloud storage of the host. So it can save the other members’ storage costs.
But all in all, I think the existing feature (shared iCloud links) is more flexible and safer than the new shared libraries. And it preserves the full resolution and quality of everything, just like the new shared libraries.