Why did the Turks fight Russia and Austria in the 18th century?

The Ottoman Empire entered a period of decline in the 18th century. On the Danube, the Turks were oppressed by the army of the Austrian Empire. Russia had the following interests:

Defeat of the Crimean Khanate in order to stop raids on the black earth regions of the country.
Creation of a fleet in the south, in the Black Sea and in the Azov Sea.
Support for the Christian states on the Danube – Wallachia and Moldova, as well as Georgia, where the interests of the Ottoman Empire and Russia also clashed.

The Ottoman Empire lost the wars 1768-1774 and 1787-1791.