Resistor VS non Resistor spark plugs

Just a bit of trivia....VW Beetles...early ones...from like 62 to 67 ( 6V ) and the 68 to 72 ( 12V ).....the leads were all rubber coated copper wire.....but if it had black s/plug connectors ( 0 ohms ), it had a 4.5Kohm resistor rotor button...........but if they had brown s/plug connectors ( 5kohm ) and a 0 resistance rotor button.
Now these days, the leads have 7kohm per foot of lead....as well as resistor plugs......but the voltages from the coils are a lot higher now.
The higher the compression ratio, the more voltage needed to jump the gap.
I built an engine, mild one, had 175hp at the wheels....then guy says he got an MSD6-AL cheap for it, so I fitted it...he redynoed it.....no other changes....200rwhp!!!.....the engine had 10:1 CR.
Having a decent spark really helps.
I found similar results for my car....std cam, 8.8:1 CR.....fitted an ICE 7amp system....made the torque curve almost dead flat from 55kmh to 170kmh....5sp manual...run done in 4th.
My 2 cents.