I’m still using an iPhone mini and I haven’t experienced any bad layouts, broken websites, or any difficulty like that. It has the same resolution of the biggest iPhone I’ve ever had (iPhone X) so things are smaller, which would make it a poor fit for someone with poor vision, but for me it’s an absolutely perfect phone. It’s frustrating to know that the perfect phone for me could easily exist, and yet Apple will refuse to make it for me. I’ll be stuck with phones I don’t like for the rest of my life, it seems.