you are magnifying the composition 4 times over
Ae is not vector based, you are always viewing the resterized result. if you magnify the composition window, you will see pixels more and more as you zoom in. this is the world of video and pixels.
if you want to scale the image you can do so using the transform properties of each layer or composition. since these are illustrator files, you can turn on the continously rasterize switch for each layer to view always at sharpest quality, even if the layer is above 100% scale.
but even still, if you magnify the composition window, you will see pixels and it will lose quality as you reach above 100%.