Superchargers are driven by belt so they dont use exhaust gases, they give boost all the time, but also take power from the engine to spool/spin unlike turbos. So if you imagine -50hp to drive supercharger but it will give 100hp back so you are still 50hp in plus. Just example
I think supercharges are better, its giving boost constantly, more revs more boost, and not one sudden kick after 3000rpm, but thats exactly what many people like. including me.
I think turbos are possibly more popular cos they dont involve as much work I would say.
I think there was thread like this i just couldn't find it.