There is a difference between 'lens flare', which can be used artistically and beautifully, and the absolute hot garbage that is iPhone cameras shooting at night with point light light sources.
Apple has a specific lens flare problem, that is exclusive to iPhone, that other camera and lens manufacturers have solved, where there are several (sometimes dozens) of green lens flare dots from internal reflections. Often more than one green dot per point-light source.
The specific lens flares that are generated by iPhones make the iPhone photos (and videos especially) shot at night - with any kind of point light source (like a street lamp), completely unusable for any thing professional.
This is a solvable problem that exists only in iPhones. Other phone/camera manufacturers have solved this issue. Samsung used to have an issue with ugly purple dots and blobs, but they redesigned the cameras and changed the coatings to eliminate or reduce the problem in their flagship phones.
A higher MP camera will do nothing to eliminate or reduce this problem.