You're comparing wrong models though? X9 and X300 Pro are both much larger than the phones I mentioned.

(I've just noticed you also used wrong models in your original comparison - while both phones are larger than the mini, the difference isn't as large as your link suggests)

The iPhone is normal phone size width and depth, but it's meaningfully shorter than just about everything else. It doesn't sound like much on paper but I've always found it adds up once in a pocket. (All dimensions height x width x depth, in mm, rounded up to the nearest mm)

* iPhone Mini: 132 x 72 x 8 (https://support.apple.com/en-gb/111877)

These two alternatives are noticeably larger:

* Vivo X300: 151 × 72 × 8 (https://www.vivo.com/in/products/param/x300)

* Oppo X9S: 157 x 74 x 8 (https://www.oppo.com/en/smartphones/series-find-x/find-x9s/s...)

In fact, they're more like the size of the full size iPhone, which, if you're sticking with your iPhone Mini because the iPhone is annoyingly large, means they're too large.

* iPhone 17: 150 x 72 x 8 (https://www.apple.com/uk/iphone-17/specs/)