I think your first three points are right.

Of the second, basically it is convincing argument for individual sports practiced collectively, like martial arts or some grouped squash or tennis course, as opposed to team sports. The goal is common yet individual: get better than you were. So there is this togetherness although not as strong as for teams. There is no need for all to be on the same level, it is enough for each 2 people pairs to be on the same level to be able to practice. Also, there are way less negative comments as you are not making the team's chances to win worse with your lower skillset.

Thanks, this is an important consideration. People who are beginner at moving and being active in general, clusmy, fat, slow, should not start with a team sport. Can I put a link into the article?