You clearly haven’t seen how bad “no-consequences cheap” can be with even simple electronics. Your lamp, for example:
Melting (under-spec or poor construction) AC wiring, poor material for the cord, switch or socket.
Melting / burning lampshade (yes, even with LEDs).
Electrocution risk - Loose connections, easily broken plug or lamp socket, switch, inappropriate (conductive) materials.**
And that’s not even considering larger-design problems - Lamps that are prone to falling over (and breaking, or melting other things), lamps that flex but not too much or they break exposing problems above, assemblies that aren’t reasonably child-proof, RF interference even.
The race to the bottom without rules is a dangerous place for the consumer expecting a bare minimum guarantee of fitness while inviting these products into their home, not to mention those most often buying the cheapest option may be the most vulnerable.
That’s where you should use something more like top / bottom /s
I think in this sense, master is more akin to the ‘recording’ master - The best version of the recording to which others are generated, and all parts merged; no ‘slaves’ necessarily just the ‘master’.