I was helping a client move from Squarespace to Wordpress, and I was struggling to download all images from their Squarespace asset/media library, since Squarespace doesn't have a bulk download option. Rather than downloading each one individually, and I actually built a completely free browser-based utility to handle this automatically in bulk. It handles duplicates and keeps the folder structure. Hope this helps anyone migrating or backing up their site!

Find it here - https://kylescheer.com/squarespace-assets/