I see some misconceptions.
Idle temps are mostly representative of airflow in the case and your ambient room temp. It's physically impossible to cool a cpu below ambient by mechanical means, which cpu coolers are, you'd need a chemical process such as LN2, peltier or phase change setup. So if the ambient in your room is 25°C, and your case has pretty dismal airflow, you can expect idle temps to be from @ 32°C upto @ 50°C. And that's going to apply to any cpu cooler, no matter if stock or the largest Noctua NH-D15 twin tower. Loads on the cpu also add to that, if the pc is running minimal processes, @ 5% load, that's idle. If it's running background apps etc that'll move up to @ 20-25% load, which increases temps. Just running a rotating background picture in windows can add 5-10% loads on the cpu.
It is not a stock cooler. it is very quiet but that makes it less powerful.
Not true by a long way, actually backwards. The most powerful aircooler on the market is the Noctua NH-D15, which also happens to be one of the quietest under loads. Also, if your cooler is over-sized or very efficient, the fans will not need to ramp up to high speeds, so remain quieter.
It's only the smaller, less efficient coolers, such as stock coolers, that have a need to get high rpm and high noise levels as a result in order to keep temps in check.