I just spent 11 days elapsed in the UK / Ireland electric system and overall I have to encounter the EU and the US / Canada systems.
The issue with the UK system is frankly a weird plug. It is huge. There is no 2 pin version only 3 pin, and imagine a 12 3 pin UK type extension cord "gang". It would likely have to be physically twice the size.
The US plug in comparison is so tiny wee cute little thing I often carry USA electrical devices and plug just a UK adapter on the end to only interface 1 socket with the UK plug.
I actually prefer to travel with a USA 3-socket extension cord, USA Powerport and a single US-UK adapter as its more flexible and smaller than doing it the UK way. A USA 3-socket is a fraction of the size of a UK equivalent. I can upload photos of my international collection of electrics if you challenge me!