I'd go for the 15 personally. Selling points in order are USB-C port, USB-C accessories compatible and reverse charging, better battery life, lighter and more balanced in hand, back glass easier to repair, latest iPhone, slightly cheaper.
You don't get promotion 120hz, always on display, telephoto lens. But the display on the base 15 and 15 plus feels smoother than 60hz to me, it's actually quite nice but ymmv. AOD is useful if you can make use of it, but not a deal breaker imo. Lack of telephoto is situational, it's probably the least used lens for most people though, and the 15 has great in sensor/crop zoom.