I'm working on an iOS SpriteKit game and I'm currently designing some images to be used as character animations in Photoshop. There are many different iPhones with various screen sizes and resolutions, because of this designers generally have to create assets in 1,2,3x multiples.
I've read a few design articles that suggest to use design your assets/images at 1x points with a small resolution like 72 and then scale it up by a multiple like 2x or 3x for higher resolution devices (like those with a Retina display).
Why would this be the suggested route, won't this cause blurring every time we scale up? Would it not instead make sense to work with a very high resolution PPI or maybe even use something like vector graphics in Photoshop?
Thanks for any help in clearing up my confusion.