Apple released a $400 to $550 iPhone SE in Apr 2020 after years of not having an updated small phone option, so I imagine many who really wanted a smaller phone jumped on that. And then 6 months later they came out with 12 mini, so I wouldn’t expect a size able amount of demand for the 12 mini would have been sucked up by the new SE.
The SE is fantastic as it’s much cheaper and works well. I switched from an XS and years of latest models and forgot how much I love thumb reader over face.
Apple Pay in particular is better with thumb reader instead of the tap, look at, tap again buggy process.