You call it simplicity, I call it a lack of options, choice, performance, etc.
The model T is simple too, doesn't mean most users needs and requirements haven't evolved.
The model T is actually quite complicated to work.
Simplicity, often equates to a lack of customization but does not equate to a lack of usefulness.
There are many more options available to customize a '70's MG than a 2007 camry but which would you want to depend upon to get you to work each day?