Targeting market segments with products for that segment is needed to build and keep market share. If you don't have low priced entry models, you miss out on a consumer segment that is relatively large with some who may move upmarket the next time they upgrade. In addition, broadening the customer base opens up the opportunity for more services revenue, which is a critical part of Apple's revenue. If you look at Apple's iPhone offerings, they have two main product lines, one for price conscious buyers (the 15's and 16e) with various features at different price points, and the top of the line split into a 2x2 matrix of size vs feature sets. That lets Apple see a customer to the model that best meets their use case and price point.
Segmentation doesn't mean you can't make good innovative products; it helps support a flagship model that may not sell in large numbers but is important by providing reliable, profitable revenue streams that support R&D efforts. It also means you don't get stuck in a bad spot in market cycles, for example having lower priced options can help during an economic downturn by offering value at a price consumers are willing to pay shaving them forgo purchases because the premium models are viewed as too expensive; and phones are a product whose replacement cycle is easily extended and thus discretionary spending.
Cook is not the overt product guy Jobs was, he also keeps a close eye on costs, but that doesn't mean he isn't also a product guy. I suspect that's why Job kept him at his side and eventually turned over the keys to him.
