If you think of the car as a three door car with much better access (passenger seat folds and slides forward) it works well.
The rear is a bit limited for large adults due to the low roofline, and the windows are very small and non-opening too, so it’s not an ideal car for regularly carrying four people , but for one or two people with occasional others it works well. In our case where we usually carry MrsW’s sticks on the back seat it would be much easy getting them in and out than with a normal five door where she has to walk round the rear door to reach them.
It’s refreshing to me that Mazda bucks the trend and tries something different. Not everyone chooses a car just for its utility.