Switches are not compulsory, they're just conventional. MK, for example, will happily sell you unswitched sockets (and without the "not to standard in the UK" warning for some of their other products).
Also not sure what you mean by "exactly the same". You can get single/double/triple in a variety of designs and colours. It's a socket - how much variation do you need?
I did not know switches weren't compulsory!
"A variety of designs and colors" I only see a very few actually available, even via the internet (when I've looked). But you're probably right. I lived in the U.S. for a while, where variety in receptacles is easily obtainable.