Why use expensive T-slot extrusion? - Hardware

Parco T-Slotted Aluminum Extrusion Products aluminum t slot rail Parco T-Slotted Aluminum Extrusion has over 80 aluminum extrusion profiles and over 2500 t-slot components that our customers can either purchase aluminum tslot framing What a lot of people forget is that a hollow tube is stronger for the same MASS, or the same Cross-Section area, since a tube several times of

aluminum t slot extrusion My question is - why use expensive extruded aluminum T-slot? I mean, for a CNC router it makes sense because you need sub-millimeter