Good collaborators listen twice as much as they pitch.

Collaboration rewards whoever is actually paying attention. Somebody who mostly pitches is waiting for a turn rather than listening, and they miss the half-finished thing another person said two minutes ago that everybody needed. Listening is not politeness in that room. It is how you find the material that is already there.

In your next session, keep your questions ahead of your proposals. Ask what someone meant before you counter it. Say their idea back to them and try to improve it rather than beat it.