Is it front or rear tyres?

Uneven wear between inside and outside edges?

It is still serviceable as no canvass/fibres is exposed yet.

I suspect your wheel alignment has problems. Any abnormal drifting to one side, noise, steering unsteady turning either left or right?

Imho this tyre picture displays a kind of unusual tyre wear.

This 'unusual' tyre wear phenomenon, if true and real (as I'm purely speculating base on your single picture without the benefit of full set of alignment readings of front and rear wheels) is NOT for lack of redoing alignment lately after 15K km travel on your part but related to alignment readings done 15K kms ago, which for some reasons was accepted as 'good' such as all greens etc .

Recheck your existing Front and Rear wheels alignment readings by a competent alignment tech and making alignment adjustment accordingly to mitigate the wear pattern problem (to me).