I don't disagree the problem is solved - I the problem in the UK is humidity is quite high most of the time and most houses don't have HVAC and there seems to be a complete lack of knowledge around ventilation - very little thought goes into it for domestic properties, so you send up with these sealed up houses under the guise of "energy efficiency" which makes people ill though mold growth due to lack of air flow. It's probably also contributed to the spread of covid 19.