Why are ten man sides our achilles?

I watch. And I see. But my brain can't fully comprehend. A team at this level with european aspirations. Why we can't break down 10 man sides. But not only that, why we LOSE to ten man sides. Quality in the midfield lacking is a reason but bruno and casemiro arent scrubs. still doesn't explain it bc even average mids outnumber the oposition. Malacia defending was horrible on that goal, bush league, and that was good work and shear will from the scorer, but what in the litteral fuc* on the whole again.