Why is my Xperia Z1 camera so bad, pictures are blurry and grainy, camera is awful too?

[AC Question]

Why is my Xperia Z1 camera so bad. Pictures are blurry and grainy. Camera is awful too.

Pictures are blurry, grainy. Camera is also blurry and grainy. fizzled out colours. It wasnt like this when I first got it. Why is this happening? I feel like I have been scammed.

Please help