There are residential jurisdictions within USA that require metal conduit between jboxes (e.g. Chicagoland) — initially more expensive, but much easier to modify/update. Flexible plastic conduit doesn't seem to offer barely any more protection than a standard US NM sheathed cable.
As an electrician of two decades, my commonest USA gripes are these:
•) grounding wires should always have insulation, too (instead of just bare)
•) modern NM isn't protected enough (neither physically nor chemically)
•) jboxes should have better wire anchoring inside, and bigger in general
•) oldwork cut-in jboxes aren't substantial enough even perfectly installed for long-term use (if you screw them to an adjacent stud they're great, but this is against code for grounding reasons).
As an electrician of two decades, my commonest USA gripes are these:
•) grounding wires should always have insulation, too (instead of just bare)
•) modern NM isn't protected enough (neither physically nor chemically)
•) jboxes should have better wire anchoring inside, and bigger in general
•) oldwork cut-in jboxes aren't substantial enough even perfectly installed for long-term use (if you screw them to an adjacent stud they're great, but this is against code for grounding reasons).