Why sprite imported into unity increased in size by 100 times?

Question

Unity

I made a sprite atlas for use in the UI and saved it as png (this file weighs 162 kb, resolution 2048 by 2048), after adding it to unity it began to weigh 16 mb, here are its settings:

I don’t use compression because the quality becomes very bad. The question is why did unity increase the size of the image and how can it be fixed? And the second question is why, when compressed, the image loses much in quality (and if it should be, then what is the point of it if the sprite beats with a ladder when displayed), maybe I'm not preparing images correctly for import into unity?
PS I do development for mobile phones

Answer 1

Some strange atlas turned out, a lot of unused space. All this could fit in 1024x1024 or even 512. Take the TexturePacker for example and pack the atlas better. There are also compression settings and more.