At the refreshments before the department colloquium each week, they used to have sugar cubes, then switched to packets, but have now switched back to cubes. Everyone seems to be happy to see them back.
I also got the oral vaccine dripped right into my mouth, with no sugar cube. I guess I was around twelve years old, and the year was around 1974.
Well, I guess it just goes to show the evil lesson of what the world is like when sugar cubes are unobtainable.
I have a box at work in case the coffee area runs out. In fact they were cheaper than a box of packets, probably because they are unwrapped.
The big disadvantage of cubes is they take longer to dissolve in coffee or tea. Good for sucking things through them, bad most of the time.
BTW, the QE2 had sugar not as cubes but as rectangular solids. They were just more elegant.
You can still buy sugar cubes if you want them at home. They are still used in Europe and are essential if you are a drinker of Absinthe. Some are still produced in Louisiana I believe but I buy mine from a company who imports them from France. The ones I get are just like the ones you find in the restaurants there today, individually wrapped. The are rectangular in shape and about 2/3 the size of the old square standard sugar cube we all remember so fondly. Or at least I remember so fondly. I like these wrapped cubes since they don’t stick together and ship well.
They also work quite well with my Hungarian Absinthe. 
Well, given that Domino still makes sugar cubes and that they’re on sale in every supermarket, I don’t see their demise as being imminent. I myself have a childish love for sugar cubes, and use nothing else for my tea. My kids do sometimes eat them as candy.
I wonder if legalizing absinthe in this country caused even a modest uptick in sugar cube sales.