How does my perfectionism hurt my team's work?

Your team knows their work will be redone, so they have stopped giving it their full effort, because why pour yourself in when it will be changed anyway. And here is the bitter turn. Your perfectionism, meant to guarantee high quality, has produced exactly the low quality it was trying to prevent. That is a hard thing to see, and you are seeing it clearly. When people know their work will be overwritten, they stop owning it. Effort drops, care drops, and they hand you something half-finished because they have learned that finishing it is your job now, not theirs. The redoing that felt like protecting quality has actually taught the whole team to aim lower. You did not intend this, but the pattern trained it, step by step. So start handing the ownership back. Pick something and let it ship at your team's standard rather than yours, even if it is not exactly how you would have done it. Give feedback instead of taking over. It will feel like a risk to quality. It is the opposite. When people know their work will stand, they raise it. You get better work by loosening the grip, not tightening it.