When using the shape builder tool against a dxf file (or vector format), the CPU usage is not high and not working.

When using Simplify on a dxf file (or vector format) to reduce the number of paths, the CPU usage increases to approximately 100%, confirming that the CPU is working correctly.
This behavior makes sense since the calculations are done by the CPU since it is a vector format.

However, when using the shape builder tool, the CPU and GPU functions are not used.
I was checking the resource monitor and the CPU and GPU usage was about 3%~5%.