By no means am I saying that "I made that" is a bad thing when it's true! It's vital to lionize people for the work they individually do, and encourage them to

By no means am I saying that "I made that" is a bad thing when it's true! It's vital to lionize people for the work they individually do, and encourage them to take pride in that work themselves. But if they use the same language to describe the entirety of a team project, not just their contribution, as "my doing" alone, that often crosses a line into toxicity in the ways you mention in your second paragraph.