Like others have said, building equivalent software is not difficult.Sorry I mean decades to refine and continuously develop to a point that it is similarly effective. China's first attempt at a CATIA like software wouldn't be anywhere close to as capable as CATIA from Dassault. It would take decades to continuously develop and refine and to build up its functions.
I mean Autodesk's first CAD version isn't going to be anything comparable to the most current one.
Commercial software mostly consists either of functions no one asked for or meaningless shuffles of the underlying technology. This is enhanced by insufficient time and budget for testing resulting in bugs that require yet more work. The end result is mostly just shuffling around in place with no tangible benefit. There are no fundamentally difficult software algorithms/functions that are being added between versions.