The people I know who used to only buy Macbooks have switched to Surfaces or those Dells and HPs that have milled aluminum bodies like Macs; and now, recently, I know several that recently bought Frameworks (and love them).
Are you sure you aren't just confusing all the milled aluminum laptops with Macs, and all the black glass slabs with iPhones? I've even had someone confuse my OnePlus as an iPhone (until I showed them that I didn't have that giant ugly notch that iPhones have; apparently running Android wasn't a big enough hint to them).
I don't know how they qualify those results; they don't publish anything resembling scientific work. Like, how do they counter-balance that Android users need to replace their phones less often? Apple users usually buy the new phone every gen, instead of every 3rd or 4th gen (Apple screens and batteries tend to die quickly); so, it seems active Apple users should be 1/3rd or 1/4th of active devices, not half.
Sales in of themselves don't mean much if you're comparing Apples to oranges (ahem) with a disposable phone vs one that isn't.
You are also saying on one hand that most iPhones are purchased by older non tech-savvy people while at the same time claiming that those same people buy a new phone every generation. That is hard to believe.
Are you sure you aren't just confusing all the milled aluminum laptops with Macs, and all the black glass slabs with iPhones? I've even had someone confuse my OnePlus as an iPhone (until I showed them that I didn't have that giant ugly notch that iPhones have; apparently running Android wasn't a big enough hint to them).