This was a project that my wife and I planned on doing almost since we moved into the house. It was a pretty straight-forward and rewarding weekend project built from quality maple plywood. We routed out the contours of the wall/moulding and openings to access the power and water shutoff valves. It’s attached to the studs via L-brackets and supported underneath by some (invisible) 2x4s.
Basically it gives us a place to put stuff that we don’t know what to do with.