From this image it is obvious that the sun is a giant trampoline which the earth is bouncing on. Summer is at the bottom of the bounce, winter at the top.
That explains why the sun is so much bigger in summer. Most theories fail to cover this simple fact and just ignore it, gaslighting us into thinking the sun doesn't change its size much during the year
Most people aren't smart enough to think about 4 dimensions. You can't easily visualize it, most concepts using 4th dimension just use math and math is hard for many people.