Does the iOS Camera Roll contain all of my photos and videos, incl. what's in my albums?
Yes, on iPhones, Camera Roll includes all photos, live photos, videos, screenshots, slo-mos and timelapses you have on your phone, even if some or all of them are in albums. You can plug your phone into your computer and copy your photos from the storage device that appears in your operating system's native file manager. You can also make a backup of your phone in iTunes and using a backup extractor tool, such as iMazing, recover the photos.