Satellites have max 20 watts transmit!

Just saw this statistic in a NASA video about the Deep Space Array.
Turns out that due to limitations in power gathering, etc. satellites transmit power is only about 20 watts! That is true even for deep space probes which have already breached the limits of the solar system.

Wow.

Imagine being able to see a 20 watt light bulb at Saturn from here.