@NathanG - I’d like to point out that the raster image format, with all its pluses and minuses, is not the only kid on the block in this regard.
The new thing these days is the vector format. Unlike the raster image, which stores everything as pixels, vectors use mathematical formulas to compute the lines and curves; the upshot is that the final image is completely scalable.
You can even do a raster conversion where you convert from raster to vector and vice-versa.
I did this once and the results were amazing.
I got a GIF animated raster image, and used a vector image program to convert it from raster to vector format.
I was then able to scale my small GIF animation to where it filled the whole screen, with no loss of resolution! Talk about an easy way to do an animation.