3% can be "small" in the sense of operationally-insignificant/low-ROI, even at Apple's scale, when you consider that they only have a handful of models (currently five) shipping simultaneously.

Figure most of those 3% would buy a different iPhone model if their preference was not available (not Android, because even if brand loyalty / ecosystem lock-in wasn't so powerful, the Android small-phone options are not competitive).

Then figure that 0.5% (generously!) of lost revenue has to pay for all the custom tooling, parts, manufacturing lines, etc.

... and it all makes an infernal kind of sense.

I'm still anachronistically appreciating my iPhone SE (Gen 1) with a 4" IPS display, Touch ID, Lightning connector, and a 3.5mm audio jack. It's great!

Except that I'll need to upgrade from iOS 15 at some point. :)