I imagine it's seen as a value-add by Apple and Dolby. Studios are forking off massive sums to build-out Atmos rigs. A savvy artists may ask for it because it helps you on Apple Music.

As for the consumer experience, I feel like Benn Jordan's video from earlier last year does a good job of explaining the situation and its current limitations: https://www.youtube.com/watch?v=5Dw3aKbw5Wo