but all those third party tools are still under development... most of them from the original devs... its much faster to start with an thirdparty tool than to develop all inhouse... xgen is ten years growing tool... would you like to wait that long... same goes for MASH or CAMd... im fine with jumpstarting a development...
That's just for 2018 PU updates. From 2014 to 2017, almost all features except Physical camera was internal development. For Maya, XGEN, new shape editor, new UVeditor, new modeling tool, MASH all from outside. I wish 3dsMax team had more money to buy more stuff. But, they did not have luxury like Maya.