Why Do I Hate Group Projects So Much?

I am a grad student in environmental science, and I genuinely enjoy collaborating on projects that align with my research interests. However, the moment someone suggests we split into groups for any class assignment or seminar project, a wave of anxiety sweeps over me. It's not that I don't like working with others; it’s more about the unpredictability and inefficiency of group dynamics. There are always those who barely contribute but still insist on having an equal say in everything. And there's also this fear that my hard work will be diluted by someone else's lackluster effort. So here I am, a person who values teamwork but hates being part of it when things get too messy and inefficient. Is it just me, or do others feel the same way? What strategies can people use to make group projects less stressful? Am I alone in hating this part of academia so much?