[ama5322]

I doubt much if we think decades. Sheet stock has always been used in conjunction to modular systems such as these, via manual or CNC machining (slots and holes are trivial to do). The advantage of a modular system such as these is the ability to build a scaffold with only straight cuts and a few off-the-shelf connectors.

In most cases you need a sheet metal press to form a scaffold out of _just_ sheet metal.

For anything structural (ie: when thickness matters), the price of custom-cut sheet stock is not that competitive anymore.

The price of machine-cut metal sheet has dropped quite a bit the last years though. I think it's filling a new niche, not really replacing the space of modular extrusions.