There is absolutely no "Maslahah" (i.e. benefit) or “Darūrah” (i.e. necessity) in Kufr & Shirk.
On the contrary, Kufr is darkness, ignorance, immoral, and unjust, hence Allah (تعالى) says:
وَٱلۡكَـٰفِرُونَ هُمُ ٱلظَّـٰلِمُونَ﴿ ٢٥٤ ﴾
And the disbelievers - they are the wrongdoers.
Democracy is Kufr and thus is a system of darkness, ignorance, immorality, and injustice. Therefore, this system of governance does not provide that which is of any benefit to mankind in general, nor to the Muslims in particular. Allah (تعالى) says:
هُوَ ٱلَّذِی جَعَلَكُمۡ خَلَـٰۤىِٕفَ فِی ٱلۡأَرۡضِۚ فَمَن كَفَرَ فَعَلَیۡهِ كُفۡرُهُۥۖ وَلَا یَزِیدُ ٱلۡكَـٰفِرِینَ كُفۡرُهُمۡ عِندَ رَبِّهِمۡ إِلَّا مَقۡتࣰاۖ وَلَا یَزِیدُ ٱلۡكَـٰفِرِینَ كُفۡرُهُمۡ إِلَّا خَسَارࣰا﴿ ٣٩ ﴾
It is He who has made you successors upon the earth. And whoever disbelieves - upon him will be his disbelief. And the disbelief of the disbelievers does not increase them in the sight of their Lord except in hatred; and the disbelief of the disbelievers does not increase them except in loss.
Indeed, there is absolutely no benefit or any advantage to be gained in participating in a process whether it be tahakum or voting that leads to nothing but hatred from the Most High and increases one in nothing but loss.
Ibn Taymiyya رحمه الله said:
أَحَدُهُمَا مَا يَقْطَعُ بِأَنَّ الشَّرْعَ لَمْ يُبِحْ مِنْهُ شَيْئًا لَا لِضَرُورَةِ وَلَا لِغَيْرِ ضَرُورَةٍ: كَالشَّرَكِ وَالْفَوَاحِشِ وَالْقَوْلِ عَلَى اللَّهِ بِغَيْرِ عِلْمٍ.
One of them is that which it is certain that the Sharī‘ah has not permitted in any circumstance neither in darūrah (necessity) nor otherwise such as shirk , immoralities, and speaking about Allah without knowledge.
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And he رحمه الله also said:
وَهَذَا لَا يَجِيءُ فِي الْأَنْوَاعِ الْأَرْبَعَةِ فَإِنَّ الشِّرْكَ وَالْقَوْلَ عَلَى اللَّهِ بِلَا عِلْمٍ وَالْفَوَاحِشَ مَا ظَهَرَ مِنْهَا وَمَا بَطَنَ وَالظُّلْمَ: لَا يَكُونُ فِيهَا شَيْءٌ مِنْ الْمَصْلَحَةِ
And this does not apply to the four categories for indeed, shirk, speaking about Allah without knowledge, immoralities (whether open or hidden), and injustice contain nothing of maslahah (benefit) whatsoever.
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