As a matter of principle, near silence is a diffcult state to achieve.
Unless you are prepared to open the case of a brand new PC and replace exixting PSU cooling arrangements and all other cooling fans with other components specially chosen for their quiet behaviour.
Dell and probably every other brand manufacturer have bundled a set of components to meet a given market where speed and capability determine what will be fitted for a given price.
Noise has very low priority.
Again with so little importance attached, there may be noticable variations between otherwise identical models.
Google will display a huge choice of quiet fans and very efficient heat sinks, some of which dont need a fan at all.
I transformed a new PC by simply replacing the PSU for one with a large, slow revving fan and the promise of quietness.
The obvious snag is that most retailers of new computers are peeved if you open the case withing the warranty period.