Why is the domestic power supply almost universally supplied at 230V?
The voltage standard is a compromise between the following requirements:


We want to keep the wire small.
We want to keep the I2R transmission losses small.
Safety so we do indeed need somewhat low voltage.  


The frequency standard is a compromise between 


Transmission line losses which mean we want lower frequency.
And transformer size.


Electrical components are designed to endure a certain voltage/current.  So a designer will never design something that has a maximum of 50 V if the main power supply is 230 V.  A good manufacturer will design a system that can operate under both 230 V and 110 V.  To do so, you will need a very good regulator for the device.