If I am happy with my job, then I don’t care about what others are doing unless it directly effects me. I picked a line of work where I don’t really have to rely on too many other people doing a lot of work for me to do my job (auto mechanic). So if someone else is working slow, I don’t really care unless its the parts person or service writer. And if they’re being slow, I will just physically stand in front of them an watch them do whatever I need right there, then I can leave and keep working.
Don’t compare yourself to other people, its a dangerous trap. Every person is different and capable of maintaining different work levels. Otherwise you mighr end up overconfident or depressed.
If someone who isn’t your boss is ordering you around, just ignore them. They’re not your boss.