You are living in the 90s, friend. MQM faced two major operations from the Establishment of Pakistan and that destroyed the militant wing of MQM--and good for Pakistan, BTW.
MQM is now a shadow of its former self, just like PPP and PMLN are. Massively supported parties reduced to nothing, as of now at least. You might not know that MQM was forced to support PTI after the 2018 elections. From an account, the leadership of MQM was literally coerced by the security establishment of Pakistan to vote for PTI or else... According to journalist Haroon Rasheed, MQM leadership was made to sit on floor until they agreed to accept the 2018 elections results and support PTI.cAnyway, the militant wing of MQM has been long gone. And so are the militant wings of PPP, Punjabi, Pakhtoon parties in Karachi--gone.
You see: Every insurgency has a life of its own. It begins, arises, gets to its peak and then dies out. Some take a long time but in case of Karachi, they arose and died in less than 30-40 years. As I said above, the issues in Karachi are basically issues of governance.