To take this a step further, IMO a big issue with how OOP is taught & practiced is that people approach it from the wrong direction. As classes provide both da

To take this a step further, IMO a big issue with how OOP is taught & practiced is that people approach it from the wrong direction. As classes provide both data and functionality, it's better to first model your data and then think about the functionality to provide on those data. But people tend to think about relationships & actions (i.e. functionality) first and model their data to that. The two approaches will tend to produce very different data structures. I'd agree with the sentiment from the OP that being data-first is ideal.