Why do we use alternating current and not direct current for mains power plugs within a house?
Within your house, electricity is still transported.

The typical voltage loss on the average household cable of 1,5mm² cross section with an average length of 50m (forth and back) from the meter cabinet to your applicance is about 1V per 1A.


1V isn't much for 230V.
1V is much for lower voltages.
For lower voltages, you need more current for the same power, so the voltage loss on the cable gets worse.


That's why you want to have 230V at your electrical outlets. But your question was about DC. Why not DC?

Because, until lately, it was highly impractical to turn one DC voltage into another. You always need electronics to do that which have some sort of DC-AC-DC inverter inside.

AC on the other hand can be transformed to another voltage by a simple electrical component. No electronics. Copper on an iron core. A transformer.