Most people don't utilize them fully.

- In the winter, if there is sun, and you have like black leather interior, it actually helps warm the car up.

-For trucks, having a glass roof is almost essential for seeing if you will fit into a parking garage. Having lived in Seattle, Im glad my truck had one.

- Opening the roof and setting AC to use outside air is the fastest way to vent the car. It doesn't create as many vorticies as opening the windows.

What you’re describing is a sunroof that’s useful for a small set of use cases. Panoramic roofs that don’t open are different.