okay, i mean, that's exactly what my original comment said: this is only a problem if you buy cheap cables.
It's also only a problem if they overcomplicate power delivery design such that you need expensive cables.
They could have made it just DC +19V and GND over 14 gauge wire with a nice, outdoor-recreation-grade connector and called it a day.
If some of your devices require a $30 cable and you use the same cables for everything, then you use a $30 cable for your mouse.