In general, salvaging material from construction demolition isn’t worth the time, with some exceptions like copper. The metal and concrete will be recycled, everything else is garbage.
A less expensive option would be woodwork that covers a channel in the wall, romex and Cat6 cable don’t need a raceway so you could skip the wall duct. If you want to get fancy, add some hinges on the woodwork to allow for easy access :D
There are lots of similar wall systems for commercial applications, google ‘wall panel system’ for some examples. It is super useful when you add something that is recessed in the wall later on.
Gypsum wallboard aka drywall is used because it’s cheap, light, it’s easy to install, and easy and cheap to finish.
For wiring at least, the wall itself isn’t the enemy, that’s easily navigable with a drill bit, multitool (or a rotozip, or a jab saw), and fish tape, it’s the dang ‘hardlid’ (drywall or wood, non-removable) ceilings that complicate things.
ACT grid ceilings make adding receptacles, switches and jacks into a finished wall pretty easy, you just drill into top of the wall, cut an opening in the wall, and use a fish tape to pull in your wire or cable, and then put in your cut-in box or LV ring and your device or jack.