Is matter wave coherence much stronger than we currently assume?

Feb 2020
Other free particles can interact without causing decoherence. Light is responsible for most decoherence. Are we breathing in quantum waves when in a completely black room?

Have we tested an unobserved matter wave without a vacuum? No light, but let there be air in it. I don't think decoherence is very fragile to other free particles that are not light. It explains how tunneling can happen in our bodies at the cell level for energy.