Make sure you understand that Islamic government, in the broadest legal definition, is not the same thing as “ideal” Islamic government.
We have not had “ideal” Islamic government for 14 centuries, but we did have Islamic government, insofar as our rulers were Muslims and the basic character of the government and its general laws were Islamically guided.
The monarchical period which succeeded the Khilafah ‘ala minhaj Nubuwwa was not ideal, but it was Islamic. Similarly, the stage we are in now, the period of Mulk Jabryy, does not prcelude the existence of Islamic government, though it does preclude the possibility of “ideal” Islamic government.
A government can be sinful, can be oppressive, can be despotic, and still be deemed Islamic, in the broadest sense of the term; and that is what we have had since the abdication of Hassan bin ‘Ali bin Abi Talib. That is what we have today, and that is what we will continue to have for the foreseeable future, with varying degrees of oppression and varying degrees of justice.