I will agree with you on DS9, which is why I rank it better than Voyager or Enterprise... but all three shows demonstrate increasing willingness to throw the principles of trek under the bus for a militant pov.
For instance, in TNG Picard decided against reprogramming a captured borg with a virus meant to wipe out the borg (one of the greatest threats to the federation) because it's the morally wrong thing to do. Janeway actively plotted plans of revolt and genocide for the borg.
Star Trek is about exploring the universe, meeting new races, finding peaceful solutions, and learning to co-exist with people that do not share your culture. And this attitude is best demonstrated NOT by the diverse casting but by the actions and thoughts of Kirk and Picard. And it is something that the newer shows don't get behind. They changed the tone for the worst. Enterprise demonstrates blind racism between humans and Vulcans; nearly every first contact in Voyager becomes militant, and Janeway always responds with force; DS9 is about breaking the bonds of fellowship to choose sides in a huge war. None of the themes and actions in the last three shows are very trek.
That's probably overstating the case, but I'm glad you raise these points. One of the cornerstone elements of Trek is its liberal humanism, its belief in universal progress and the power of reason and good-will to solve problems.
In other words, it's hopelessly fake

Seriously, I'm glad they made Janeway more of an ass-kicker because it gives us some contrast with
Mr. Rogers Captain Picard and intentionally raises moral dilemmas: you're a gajillion light years away from the Federation you're supposed to represent, you have no backup and no recourse to higher authority, what do you do? What's more important: survival or honoring an abstract principle?
As for first contacts becoming militant, that's a reflection of reality. Not everyone wants to talk or respect your person or your values. They want your wallet or your territory and will kill to get it. Of course, how real do you want to get with escapist TV?