This extension takes the points of a path and make a straight polyline out of it. Nothing less, nothing more. ou can do the same with default InkScape UI but it might be quicker to use in some use cases. This extension handles duplicate points on a path by removing them. This extension is similar to Flatten Beziers but works much easier (but has less control over elements).
Red outline is original curve, black one is the converted one
Left is before, right is after conversion