Machen tried to fight off the liberals in the old PC US, didn’t work and the OPC was born. Only catch was they lost their grand old churches to the liberals.
Fast forward to the 1960s/70s and the PC US merged with the more conservative old Southern Presbyterians. The PCA was born out of that merger. PCA churches lost their buildings.
The PCA is set up so that the local congregation owns the building, not the denomination. I think that helps keep things in check.
It was impossible to negotiate with the ECUSA. They would not even consider selling the buildings back to the exiting congregations. They did sell the buildings to Muslims and “Oneness” congregations, but not to evangelical Anglicans.