Denver driver/transit-er here. Cars aren’t automatically better than transit in many cases.
The rail is nearly as fast and much less hassle along the I-25 corridor, which is why I take it. My route is probably the most optimal of course as I both live and work near a light rail station.
I’ve commuted from south Denver to Boulder and that is about 30 minutes longer using Public Transit, but that’s largely due to transfer waits.