Since political correctness is (more or less) egalitarian in its aim, it is superficially hard to explain why the PC is so power-seeking: why they seek to subordinate every human decision (public or private) to government regulation. Surely this is to favour one group (the PC elite) above all others?
The answer is simple - albeit unconvincing.
The aim is to take all power into the PC elite, who will use this power to make the world safe for PC - by using power to extirpate all trace of resistance to political correctness (all trace of racism, sexism and the various 'phobias') - and then to relinquish this power.
More exactly, to install systems that prevent all forms of prejudice - then when these systems are indestructibly installed - to walk away from power.
So that no individual human being or group of persons will have any more power than another human being or group of persons: all will be subject to the same algorithmic processes of social justice.
The unconvincing bit is that there will be nothing and nobody that makes the PC elite walk away from power. There is only the PC elite's trust in their own good intentions, and trust in their own ability to carry-out these good intentions.
Of course, the time to walk away from power will never come if there is any residual trace of non-PC resistance (real, or imagined)...
And since PC is social constructivist (believes neither in God/s nor in human nature) this means that to ensure they will indeed walk away from power, when the time comes, the PC elite must be sure first to brainwash themselves completely and irrevocably...