it all depends how it is done. Technically it would also not need to be done instantaneously.

agree, but then again you appear to have missed where I said

|battery autonomy for 20-30 miles (in case of power failures, looong driveways....)
I did not say that it will use the "powered roads" the whole time, the 20-30 miles was an example and what I believe to be sufficient with no extra research, if 50 miles makes more sense then it can be 50 miles, there can even be different distances for different car models. The idea behind a powered road is
1) most roads do have power around them so the issue becomes making it available in a safe way to vehicles
2) there ate two issues with electric vehicles as they are today
-- a) batteries - the main theme of this thread - and this will reduce it
-- b) fill-ups - let's face3 it, it is nice to say there are many supercharger stations, but if you are going far do you want to drive for 3-4 hours (or even less) and then be forced to stop for a fill up that takes an hour (or even more). With a powered road you could drive from one corner of the country to the opposite corner with out being forced to stop (let alone for long periods).

agree, but that is why I gave the example of tramways/streetcars as well as my phones charger.

Montreal had electric trams from 1892-1959, Toronto old street car system might have newer cars but it is still in use as it has existed for ages.

and I can touch the pad and there is no shock, actually they even make plugless electric car chargers https://www.pluglesspower.com/ but since I have never used one I can only assume it is fast (i.e lots of power) yet safe (I.e I won't get electrocuted if I step on it)

you are also missing the obvious, Volts and amps need to be high if I want to charge an electric car fast, if we have powered roads then both of those could be low since all you need is enough power to maintain power.