Morning Joe on MSNBC regularly interviews Republican members of Congress and have interviewed members of Trump's WH staff. The Sunday network news programs regularly interview both Republican and Democratic members of Congress. CNN interviews people from both sides of the aisle and have Trump and Republican leaning members on some of their panels. It's not a belief or opinion on my part, it's a fact. I know it because I see it with my own eyes and hear it with my own ears.
I don't know what programs you are watching, but to say that FOX is the "ONLY" network to let the "other side" (by "other side" I assume you mean Republicans and conservatives) is simply not true.  But facts and truth obviously have not been an important component of the Trump administration, so maybe it's not important to you either.    
By the way, is Mitch McConnell and some of the Republican senators crafting their new "Health Care" bill in secret the way to make America great again? Whadda think?