When do you intervene at the playground? And do you guys wear masks?

When you take your kid(s) to the playground, what do you watch out for? What will prompt you to step in? How do you handle it when your kid has a negative interaction with another kid?

Also, I'm so confused about mask wearing. I had thought that we don't need to wear masks outside anymore, but I sometimes see parents wearing masks. Sometimes all the parents wear masks. Sometimes all the parents are mask-free. Sometimes there's a mix. I usually put on a mask when I see other parents wearing masks just because I don't want to make anyone uncomfortable. What do you all do? Do you ever feel uncomfortable when parents/kids aren't wearing masks at the playground?