I don‘t think this is quite the same. Most warmongers get bonuses for exactly that. So, if you don‘t fight and conquer, you‘re losing out on your bonuses/uniques. There is a clear benefit of waging war for all civs/leaders usually, because this is how the game is conceived and designed. And this benefit it even larger with a militaristic civ/leader. But as a pacifist, you don‘t get a good compensation for being peaceful - in almost all cases, you are better off conquering as well. Especially in high level civ VI, letting the AI build stuff with bonuses and taking it is better than staying at peace trying to outperform the AIs bonuses with their own stupidity only.
On the contrary, being warlike in Civ VI got you universally condemned by every other power forever: take one capital, and it would be Eras before you got another trade agreement of any worth, and you would also get negative diplomatic points, be outvoted in every World Congress, and so on.
Mind you, none of this was enough to avoid winning the game by Domination, but that is a matter of game balance, which has, frankly, always been in favor of the human player in combat, and the abysmal state of the AI in Civ VI, which was and is utterly incapable of forming any alliance of Civs against an aggressor.
Although, I have also played utterly Pacific games in which I aimed to win by never declaring war, never fighting except against barbarians, and only 'taking' foreign cities by peaceful flipping or taking advantage of cities reverting to Free City status - and won a diplomatic victory that way once before Turn 220.
That was with a Leader not considered particularly advantageous as a Cultural or peaceful one, so I'd say if anything, 'pacificists' get plenty of advantages (or did get in Civ VI) just as 'warmongers' did - IF they knew how to play them. - And I freely admit it took me quite a few tries to get used to playing a pacific game and using the advantages available in that mode. It is certainly less obvious than combat advantages are at first glance, whether they are attached to Civ or Leader.
So, to me it depends on how the diplomatic and other 'systems' in Civ VII are applied and interact with 'loyalty' and 'culture' to determine if pacifists will need anything special as bonuses or maluses, but the fact remains that to provide blanket maluses to one entire class of Leaders and only one is just bad Game Design regardless of how 'accurate' anyone thinks that might be.