The UK is not in the EU and use all kinds of weird units and other nonsense. If they had stayed in the EU long enough, they would have caught up eventually, as will Italy.
I doubt we're changing the side of the road we drive on, but now it's much more expensive to import LHD used cars from the UK. I doubt that we're changing power plugs because there's hundreds of millions of them out there.
I'm not sure that other EU standards there would be that we don't have, being an EU member, except for decent cycling and mass transport infra, and that would be dramatic improvement.
Having travelled the EU with Irish/UK plugs on my electronics, it's a pain in the ass unless you have swapped the plug on several power strips.
Also, basically all of the adapters say not for long term use, and they're nowhere near as stout or secure as either type of plug alone.
Anyway, the UK plug is the best one out there, except for stepping on them. They're worse than legos, and that's saying something. (and maybe size, weight, and cost. But electrically, they're good)