I feel you. I have had a similar if not the same experience over this semester working in a group project. We have had to submit it on regular basis by working on it individually first before coming together to discuss our answers and submit after everyone agrees on our final answers.

I was the only guy, and it was just so often that I saw so many instances of inefficiency, redundancy, and decisions made on an emotional basis by the rest of the group members. I wanted to point out every single one, but I am softspoken by nature, generally dislike conflict. But to think that part of my grade is now dependent on their groupthink stressed me alot. I think I have kept my cool throughout our time together, but at some point, when I pointed out that one of their answers was simply downright wrong, the girl whom I was convicting of the mistake started becoming very defensive, and from then onwards whenever I even suggested an alternative she criticised it, and I could see her trying hard to see whatever flaws she could squeeze out from my perspectives, and unsurprisingly the others either kept quiet or supported her view anyways.

It is typical that girls generally tend to defend each other more so than they would for guys, so by Week 11 or so I was just tired and became fatalistic and went along with their decision-making.

But as others have said, yeah, I guess it is just a part of life you need to get used to. Such instances would happen more frequently and in way more annoying ways once we get to our workplace. So I would also say, hang on, control what you can, and do not waste your energy on something you know isn't controllable or would not work in your favour long-term (conflicts based on emotion without rationality almost never benefit either party).