Lol. If that is your issue with newer Trek, why do you list DS9 as great? Or (later) TNG? VOY is boring, unnecessarily devoid of most character development but still carried much interpersonal conflict. LMAO.

DS9's interpersonal conflict were in context of being set on the outer fringe of Starfleet's reach, showing how the goodness could be brought forth to where there's conflict, where the ideals of the federation and starfleet have not yet reached and settled. None of Trek, from the start, was that everything is effortlessly hunky-dory la-la land positivity-ninnyism across the cultures of different species... it's not all magically balanced already without effort. There's great effort to balance and achieve peace, so we can all explore space, both inner and outer, together, forever, in peace.

Note the absence of interpersonal conflict among those of the federation? Even where there's tension, the peace is kept, and friendships form. It's not juvenile insanity. Even for those who set out to go into starfleet (or not), like with Nog and Jake. It's still an aspirational hope for the future, even in interpersonal relations. Instead of the tension that is allowed, across the different species of aliens, being solely who are met by the crew of the star ship Enterprise, everybody's brought together on the space station, Deep Space 9, with no running away. Everybody there, seeking a better future, even the antagonists, in their own way. Well considered characters, with their own perspectives and philosophies. RedLetterMedia recently did a quick two part run through of season 1 of DS9, in which they touch on some of these well thought out fun aspects: https://www.youtube.com/watch?v=u5ozNRUW7Kw https://www.youtube.com/watch?v=SXYFrc1-ES8

VOY's little rubs of interpersonal conflict here and there, were almost entirely from the Maquis and Starfleet, learning to get along, forced together by circumstance. Generally more strictly in line with the principles of Star Trek, the same structure as Gene gave us, the crew get along (quite astonishingly, really, considering the radically different views the two crews have, ~ that they become one crew... how about that for putting aside the differences? We should all so aspire.).

Maybe I'd need to rewatch TNG to get what you're on about there. I don't recall TNG having nearly every line of dialogue be spitting foul mouthed adhominems in searing hateful tones, like SFA has. Nor even any such lines at all. But maybe I'm misremembering. It has been a few years (... Gosh, maybe about 7 or more years) since I last watched all of TNG. But I could understand the writers taking the cheap easy way out once slipped free from the living reigns of Gene Roddenberry.

Later TNG, DS9, VOY, may have pushed the boundaries. They didn't betray the boundaries that defined what Trek is. They stayed consistent in that universe.