Stars and nebula are really big. If you can for example see a mountain that is 30 miles away with a telescope that doesn't mean that you can count the eyelashes of a person only a mile away. The mountain is so much bigger than the eyelashes that even at that distance it is much easier to see.

For example the Carina Nebula is 230 light years across, while a planet like Jupiter is 139,820 kilometers in diameter. So that is 139,820 kilometers across vs. 2,176,000,000,000,000 kilometers across. Even if the Carina Nebula is much more distant it can be easier to see than Jupiter.