Perhaps the most successful attempt at convergence so far has been the Europlug, but only because it's a weird compromise. Did you know the europlug prongs aren't actually parallel? They angle inwards slightly and have a little flex, so they can be accepted in multiple European countries' sockets that actually have slightly different dimensions! It's a cool design, but you wouldn't intentionally design it that way if you had the opportunity to standardise the world from scratch.

[–] SlurpingPus@lemmy.world 1 points 23 hours ago

The Schuko plug/socket are the ones that are both grounded and reversible. And are used in most of Europe.

Oddly Poland, Czechia and Slovakia went with the French standard, which isn't reversible. But helpfully the CEE 7/7 plug is compatible with both that one and Schuko.