As a XS user, I've been waiting for a small phone since 2014.
The 5 was perfect. Going to the 6 was too big, and the XS is even bigger. Having colors on the 12 mini is awesome! Getting a green 12 Mini, 256GB. Honestly, if they put new guts into an iPhone 5 shell, I'd buy it. But I'm sure not many people feel this way.
Yeah, you and I are in the same boat. The 6/6s had no appeal to me whatsoever due to the size and shape. (Felt to me like Apple chasing Android.) The surprise announcement of the OG SE with 6s guts in a 5's body was an instant order.
The first iPhones since that interested me since were the X and Xs (still the best iterations of the 6 design), but in hand I just couldn't bite the bullet.
I think the Mini is the closest thing to the much wished-for "SE-X", combining the X's innovations with the classic Jobs/Jony design for the iPhone. I think what's telling is that my SE and 5s design wise seem to look better (just as objects) and more up-to-date than the 6-8s I see around.
In a way it's like how the last two 'boxy' generations (~1979-1999) of Mercedes cars (the pioneering design work of Bruno Sacco) still look like striking classic cars, whereas the overly curvy [and poorly engineered but that's a different story] 2000s models that followed look very dated.