5-6% of sales ABSOLUTELY matters. The biggest question is really will the majority of these purchasers substitute the absent "Mini" model with another iPhone model? If 90% of those users will just buy a different model then there is little advantage to offering the mini, given the additional design/engineering costs of the smaller size.

Anecdotally, I'm a techie but a small phone die-hard. I help onto my original SE until they finally released a mini model and will likely do something similar with mini 13. They definitely lost some potential upgrade sales from me, but despite that Apple STILL has the best tiny phone offerings, they are still software and hardware supported by Apple, although you have to purchase refurbished. There just isn't a serious Android competitor, with any sort of long term commitment to small phones, that would justify the switching cost.

My opinion is that Apple botched their positioning with the mini. "Mini" is a diminutive term, it implies less than. It was the lowest pricing outside of their SE model. They released the 12 mini shortly after an SE release, leading to cannibalized sales. And they released it at the beginning of a period (ongoing) where Apple leaned into the messaging of "Bigger is Premium". The only people left to buy the mini were people obsessed with small phones.

I think a more successful product would have been to lean into their "Air" brand, leveraging Apple's known ability to engineer premium devices in the smallest, most-elegant packages; positioning it as a premium product orthogonal to their main iPhone line. And from the rumors, it sounds like this might be Apple's next move in a device market that is increasingly undifferentiated.