This. Product Management at just about any company is about what can be provided to drive sales now. Holding back features that are deliverable now only creates risk and lost revenue.
Reasons that such features are left out are generally related to time to market (TTM) or driving COGs up to a point that it can't meet margins for the targeted price point.
However, there is another reason that I can think of:
As a company that clearly withholds features, look at Canon. They withhold features like crazy. Why do they do that? It's aggravating, as a serious hobbyist on the Canon side. And, if Canon does it, then why would I think Apple doesn't?
Canon largely withholds features to protect other products it sells. It basically cripples lower end products in a few key ways to prevent cannibalization within its product family. Beyond that, they likely operation like other companies.
Apple, however, doesn't have other existing products to cannibalize from. There's only one model a year, so it's only cannibalizing from the older models, which is what you WANT.