The iPhone 13 mini is without doubt the best small phone you can get. The few competitors that exist are usually cut-down, cheaper models with compromised experiences, where the 13 mini is a full iPhone, just condensed.
Pros: small and easy to hold, great camera, water-resistant, MagSafe, Face ID, top performance, great screen, 5G, long software support.
Cons: no USB-C, need your own charger, no telephoto camera, screen may be too small for many, not cheap.