That and switches (like light switches): not only we've got way more variety in the EU but they also all feel of better quality.
Both electrical outlets and switches in the US do also look old and dated. Just like they feel when using them: old and outdated.
It's just all really weird, nearly anachronistic.
So, when I arrived in Barcelona and Catalonia, I was pleasantly, mildly surprised that not only had Europe kept pace with us techno-mages in America, but they had some kind of parallel evolution going on, in terms of connectors, interfaces, protocols, etc.
My fiancée was sort of mystified, because my favorite subject of photography was not landmarks or her pretty face, but the circuit breaker box, the rear of her television set, the A/C unit, and any other cool, distinctly Euro-tech instances I could identify around there.
I tried helping her adjust/fix her aerial TV antenna, got zapped a few times; discovered that Catalonian TV antennas are energized with a few volts for whatever reason; decided that Euro-tech is beyond my expertise to tinker with on someone else's behalf, especially a native family.
Thankfully, I didn't have any portable electronics or appliances in my luggage that needed adapters or plugs, but the experience was truly humbling, and eye-opening, and I returned to the United States with a better calibrated worldview.