There are distortions in the way we see our universe, due to the limitations of our instruments. Take the Hubble Deep Fields, for instance. They show us that even the "emptiest" looking fields in space are loaded with high-redshift galaxies. However, these images cannot be assumed to show us representative galaxies at high redshifts because only the largest, brightest, most energetic galaxies will register in the images. Taking images at the limits of our instrumentation shows us outliers, and those outliers should not be assumed to be typical galaxies at their redshift.
The Webb telescope will allow us to probe deeper into the infrared and get a better view of objects whose luminosity is less energetic. That will augment our current capabilities and give us a better overall understanding of what is out there, but it is no panacea. We are limited to observing our universe from our vantage point, and interpreting our observations from our own experiences. Most humans are used to examining things in visible light, but observational astronomers look at the universe in many other EM bands, including X-rays, IR, and radio waves.
Observational astronomy is subject to Malmquist bias (please Google it) in every EM band that we observe in.