Bigger wheels

Sorry if this has been asked before but I have read a number of posts recently about bigger wheels and if you have bigger wheels you need lower profile tyres to keep the wheel radius the same for the speedo. So what is the point of bigger wheels?

A number of reasons:
Looks/styling
Lower profile tyres can make the steering sharper
Lighter wheels can improve handling
Wider wheels may help with grip

Cheers. Interesting.