As already explained those big PC boxes designed to waste hundreds of watts need to be powered by an ATX PSU that all perform very poorly in low-load situations.
Here some guy tested out 4 different ATX PSUs with the very same setup (same mainboard, same CPU, same DDR4 stick, same SSDs) and measured with those four different PSUs 21W, 26W, 29W and 34W ‘idle consumption’ at wall.
That’s 13W ‘idle consumption’ difference by PSU choice for the sole reason ATX PSUs designed for +500W performing crappy below 50W. Interestingly the PSU that stopped its internal fan below 200W was not even the most efficient. And with a properly chosen picoPSU the same setup might run below 10W in idle.