Place a well insulated wall in the middle of a field. Add a tripled glazed window and 100% efficient ventilation. Which side of the wall is warmer than the other?

Ideal indoor air quality is equal to outdoor air quality. This can only be achieved through air exchange. The ventilation process may be 100% efficient but the consequences of pumping outside air in and inside air out are the same. The air must be heated and costs some unit of energy to accomplish.

That's why the heat recovery is done. It of course doesn't get all the heat, but AFAIK can capture some 80%. This is in use and widely deployed.

https://en.wikipedia.org/wiki/Heat_recovery_ventilation

> Ideal indoor air quality is equal to outdoor air quality.

Ideal indoor air quality is (can be) better than outdoor air quality. This is because when the outside air is brought in it passes through filters to get rid of things like dust and pollen.

> The air must be heated and costs some unit of energy to accomplish.

Unless you use passive solar thermal, i.e., let the sun heat the home:

* https://www.energy.gov/energysaver/passive-solar-home-design

Modern mvhr systems are 90-odd% efficient. The losses through proper ventilation are small enough.