As someone holding onto their iPhone mini 13 for dear life, I hope they will release a one off in a few years once support for the 13 mini ends.
This is just an anecdote but I owned every Google Nexus phone they made up to Nexus 5. A series of bugs caused priceless videos to get ruined and I decided to try iPhone after that. I didn't realize just how much I unconsciously hated using the Nexus phone and that contributed to me not actually adopting smartphone software until I got the iPhone. When the phone and the OS were a burden it led to the phone being avoided. I dont know which was better. I appreciate the battery life, camera and general stability but I hate the new addictions to social media it has caused.
People don't know what they want unless you give it to them.
It could be assessed by a study, I have opinions until then.
Arguing against myself, Apple could be discontinuing the smaller models because they did market research and found that most buyers of smaller, cheaper devices could be converted to buyers of larger, more expensive devices if those smaller devices didn't exist. Auto manufacturers are doing just that, discontinuing or enlarging smaller light trucks in favor of larger models that are subject to less regulation and therefore can be designed and manufactured more cheaply and might offer even more profit.
If Apple has or had that strategy, then my assumptions are flawed because no matter how many mini iPhones they sell, they would still want to get rid of the line as long as most of those customers could be converted to full-size iPhone customers.