Only if you establish a single metric by which all moralities may be judged. I may judge one morality as good for keeping poor people from consuming productive capital, and another as good for advancing the arts and sciences, and yet another as good for ecological sustainability. No single value system is universally superior, because there are always tradeoffs.

It's like asking "what is the best alignment in D&D?" Paladins will say lawful good is the best because their god likes it, but sneak thieves are more likely to espouse chaotic neutral, because it means they can pay their taxes with money cut from the collector's purse, then steal it again after the ledger is dry.

Or it's like asking "what martial art is best?" That depends on what you use it for. Exercise? Military? Police? Organized crime? Bar fights? Action films? MMA competition? Wushu exhibitions? Selling colored belts to suburban kids? A military system like Krav Maga is not going to work well in competition, because nobody can voluntarily fight if everyone in the league is currently dead, permanently disabled, or recovering from severe injuries. Likewise, a movie style like "Gymkata" or "Gunkata" is useless for any real-world application.

Besides that, people do adopt other moralities. It's where many of the cult followers and disciples come from. Does that mean it's superior, or just better for that specific person, at that time?

So now your tribe and this hypothetical torturing tribe view each other as inferiors. You're "weak", and they're "cruel". Now what? Do you boycott and embargo trade with them? Do you go to war preemptively, or only after one of yours gets tortured by one of theirs? Perhaps you launch a propaganda campaign to depict them as mindless savages that revel in the pain of innocents? Maybe you single them out at the border, and loudly demand that they publicly pledge to not torture anybody while they are visiting your territory? That isn't likely to make them stop torturing.

I'm not seeing your point. An argument from morality only works for people who share your morals, a group that necessarily excludes those people who engage in torture. People who share your morality already don't torture. An argument regarding the efficacy of the technique is more likely to get a torturer to stop, whereas the moral argument only reinforces a pre-existing aversion. And thanks to cognitive dissonance, the longer someone has been torturing, the less likely they are to listen to anyone telling them that torture is wrong. If you reframe it as an evolution in effective interviewing technique based on recent scientific research, they have a psychological "out" that allows them to stop torturing without having to reframe themselves as a bad guy.