The Photos tab sorts by date, yes...but the date that's IN THE EXIF DATA. Date taken, not date added.
That's the problem.
Pre-iOS 8, if I saved a photo from a website it would show up right at the end of the Camera Roll, easily accessible and easy to find.
Post-iOS 8, if that photo is from, say, the middle of last year, it gets mixed up among the hundreds of other photos I took last year and I have to go hunt for it.
So no it's not the same. There should be a toggle in the Photos view to switch between the "Collections" view and the old camera roll-style simple "grid" view.