Do we really need interchangable lens cameras?

How much do we change lenses? Yes, I changed when I go out for photo shooting.

Do you like weight, size of these kind of camera? Yes, It makes me look like a professional photo grapher.

Do you like it's performance? Yes, very much.

Do you like price you got to pay for these cameras and lenses? There are lenses from cheap things to expensive's.

So, why are we buying interchangable lens cameras?
Everyone has a different satisfaction and I love high quality photos from dslr.