I don't know much about electrical hardware, so forgive any naivety. Anyways, I've been wondering: since 2 prong plugs (the reversible ones whose prongs are the same size) can be plugged into a socket two different ways, don't they have to include more complex circuitry than their non-reversible 2 prong brethren to allow for the electricity flowing two opposite directions?
If so, then why do manufacturers do this? Is it just cheaper, or is it motivated by consumer convenience?
Based off of the relatively small sample of plugs currently available for my investigation, it seems to me like most reversible plugs are found on charging devices (e.g.: phone or laptop charger, which all have the colloquial "brick" included), while plugs built into electronics and other hardware (e.g.: a power cable for a TV or a lamp, none of which have an external "brick") do tend to have 2 prongs, but these are differently sized, rendering the plug non-reversible.