You were always more than your output
Once we've worked on something long enough, it starts to feel like an extension of ourselves. We see our decisions reflected in it, so criticism of the work can feel like criticism of us.
That emotional attachment makes it harder to judge the work objectively, so we might end up defending a project to protect our ego rather than because it's the right thing to do.
The thing is, most of what we make at work was never ours to begin with. It lives in our employer's repo and ships under their name. Someone will rewrite it after we leave. Tying our identity to that is a bet we can't win.
What we keep is how we think. Our judgment and taste go with us to the next job.
However, separating the two is hard. I've blurred the line more times than I'd like to admit. I still care about my job, but I try to keep my identity out of it.
I've found that the best way to do that is to redirect that energy toward my own creations: side projects I build because I want them to exist. I don't need anyone to grade them. I build them purely for joy.
Each project is a snapshot of how I think right now. When I tear one down and rebuild it, I'm not conceding the old version was a failure, but I'm watching my taste and judgment evolve.