I can say from my personal experience that the moments that felt the most lonely in my life were the days I spent going to the university library working on pro

I can say from my personal experience that the moments that felt the most lonely in my life were the days I spent going to the university library working on projects / thesis, seeing hundreds of people around me, but not being able to interact with them. Everyday my brain was punishing me for not engaging in possible social interactions. I spent two months traveling alone and didn't felt lonely at all. So yeah I think the negative effects of loneliness are just the consequences of a natural mechanism to force us to be social.