YMMV. Truer than ever.
I feel the 12 mini is a bit small as stated above. I am considering reverting back to 6.1" iPhone 12.
It sort of depends on what you use your phone for - in my case: I do not own a computer or iPad. My phone is my "do it all". There is very little non-work stuff you can't easily do on your phone. With a BT-keyboard for mails you are pretty much covered. All things communication, personal finance and so on are a lot easier on my phone than logging into a computer.
If your iPhone is your "phone, text and messaging hub" and you are on the move a lot I can really see a need for a small device.
The 12 mini is a gem. For those who want a phone not on iota larger. But I think many get the 12 because of larger screen, larger battery, better speakers, better magsafe. Many use both hands on their phone regardless of size - then 6.1" is a lot better to type on.
I came from iPhone 11 - the regular 12 is actually a bit compact in comparison. People using 2016 SE's will find it unusably large.