They call the car the same as they did the year prior.
And Apple is calling all iPhone an iPhone, just like Chevy calls all Camaros a Camaro. Chevy differentiates models by model year and trim level. Apple differentiates iPhone models by a model number and a modifier.
Typically with Automakers, a certain model will be based on a certain platform virtually unchanged for about 5 years. During this time there will be insignificant changes to trim level equipment (This year the SE comes with reverse camera and heated mirrors, where last year you needed the SS), and the grill and taillights may change slightly yet be interchangable, but the underlying engine, transmission, etc will be the same. Go to the parts store and the brake parts are the same for all 5 years. Yes there will be improvements in this period, but these are usually technical in nature, and (sometimes) backported to older models of the same generation (replacement part substitutions, recalls, TSBs, "customer experience programs.")
Usually after 5 years the platform will be mildly refreshed. The sheetmetel will change, the instrument cluster will change, the wheel design will change, but underneath the same powertrain, brakes, tire dimensions, etc are there. The manufacturer will sell this model for another 5 years, giving a total of about 10 years on the same platform, before doing a large re-engineering of the platform, even if they give it the same model name.
In the Camaro example, there are six "Generations" of Camaros spanning 42 model years.
With iPhone at best the n, and nS models are similar, but the between those they are different.