In hindsight, I realised that I was coming from an Android phone a few generations back (Pixel 2) which I considered to be a reasonable size. Pixels have gotten about 10 mm longer over time. However now we have wall to wall screens, it's quite a difference. The iPhone Pro is the same form factor as a Pixel 2, for example, but is all screen. 6" seems doable for Android, but that's a lower bound.
I think what we all want is a Pixel 2 without the bezel. There are lots of phones with smaller OLED displays, but none without the bezel.
While the rumors themselves are usually pretty accurate, the interpretations and conversations around them remain pretty wild and emotional. Low sales numbers probably proved that the mini isn't the format that needs a refresh every single year and the 13 mini was unique because the 12 mini had a few weak points that needed addressing.
I think Apple has lately really had it's sh*t together when it comes to strategy and timing lately. They knew years ahead of time that the interest in the small format (in which you can reach across the entire screen with your thumb) would return as soon as everyone got used to and bored with big screens.