I think you said you've been to the UK Peter in which case you have seen them maybe just not noticed. These are typical, especially the white one though many are now supplied as shown with the facility to change fuse without removing the plug top, especially the moulded type pre fitted to appliances.
They are outdated tbh as modern circuits are protected by RCDs and MCBs which trip much quicker than a fuse and reset easier, however, "belt and braces" system is no bad thing in my book and a damn site safer than much of what I've seen in various parts of the world.
