I’ve got hands that are maybe a little larger than averages. Up until this year, I’ve always bought the largest size iPhone every time one was released. I don’t necessarily think they’re too big. I think the size in conjunction with the weight is what makes them inconvenient/uncomfortable to pocket and handle. Since going with the 15 Pro (my first time choosing the smaller model), I’ve noticed less wrist/thumb strain and how much easier it is to carry- especially in thinner/looser clothing like gym shorts. I miss the screen real estate, and more importantly, the battery life. But I’m enjoying using my phone more comfortably and the way a phone was intended to be used- with one hand.
The first few generations it was because it was the best phone on the market by a long shot. Now it’s just the ecosystem, familiarity, and aesthetics for me. I’d lose so much connectivity with my many other Apple devices if I switched that it just doesn’t make sense for me to leave. Plus it’s still a top tier phone that meets all of my needs, except battery life.