Omni-Avatars not Dashavataras

Dashavatara (/ˌdæʃəˈvætərə/; Sanskrit: दशावतार, daśāvatāra) refers to the ten primary avatars of Vishnu, the Hindu god of preservation. Vishnu is said to descend in form of an avatar to restore cosmic order. The word Dashavatara derives from daśa, meaning 'ten', and avatar (avatāra), roughly equivalent to 'incarnation'. 

Lord Vishnu has had infinite avatars in this particular world. Currently, he has many avatars in this world in this timeline, rays from the higher infinite self, in his preservation and creation mode. However, he has not found anyone worthy to preserve or save the universe for. He may as well turn into Shiva to destroy this universe, because he finds it unworthy of preserving.