This is equivalent to something I called the "QWERTY paradox" more than a decade ago:
Back when the Smartphone market exploded, people disliked typing on a touchscreen and repeatedly stated that they want a device with a physical keyboard.
There was plenty of evidence, surveys, market studies, trend predictions, devices for these "Messaging-centric" use-cases were always part of this market-demand roster.
But whenever someone answered the call and built a Smartphone with QWERTY keyboard, the product failed commercially, simply because also to people claiming they want such a phone, at the point of sale they were less attractive than their slimmer, lighter, all-screen counterparts.
Every major vendor went through this cycle of learning that lesson, usually with an iteration like "it needs to be a premium high-spec device" --> (didn't sell) --> "ah, it should be mass-market" --> (also didn't sell).
You can find this journey for every vendor. Samsung, LG, HTC, Motorola, Sony.
The same lessons were already learnt for small-screen devices: There was a "Mini" series of Samsung Galaxy, LG G-series, HTC One, Sony Xperia. It didn't sell, the numbers showed that it didn't attract additional customers, at best it only fragmented the existing customer-base.
Source: I work in that industry for a long time now
The real reason the iPhone mini failed is not related to screen size, it's because its segment was canibalized by the cheaper alternative, the SE. The 2020 and 2022 sold like hot breads, wherehas their screen was almost an inch smaller than the iPhone mini. This is the proof that there a significant market for people who don't care about size and would gladly take the smallest option at a $100 discount from the regular one.
The mini could have been simply, iPhone. The marketing would have been that they managed to add an extra .7" of screen, while reducing the overall size and weight. That's a great pitch. Who doesn't want a bigger screen in something that more easily fits in their pocket? Instead they called in a "mini", people thought it would be tiny and hard to use, so they didn't buy it.
The iPhone 12 mini screen was only .1" smaller than the screen on the iPhone 8 Plus... the giant option from just a few years earlier.
The mini was a marketing and brand strategy failure, plain and simple. It wasn't a small phone.