The word toast in the sense of "toasted bread" is an English coinage from the early 15th century and originally referred to bread that was added to wine or ale for flavour (and possibly to soak up the dregs). In that context, a mass noun made more sense than a countable one, since toast didn't come in slices. It was only in the 17th century that toast started being eaten on its own with a spread.
The word toast in other languages meanwhile (such as Italian) is a modern borrowing, and so is more likely to be countable.
Update: a bit more investigation shows that the situation is more complicated than I suggested above. Early examples in fact sometimes use toast as a countable noun, despite referring to a piece of dipped toast: for example "Go fetch me a quart of sack, put a toast in it" from The Merry Wives of Windsor (1602). I'm not sure when it became exclusively uncountable.
A cursory Google search suggests that the majority of attestations of the plural infrastructures will be found in books and articles authored by non-native speakers. (I know, I know, a name is not conclusive evidence of anything).
In the American press, we tend to see and hear the singular infrastructure used as a non-countable noun that encompasses sewage, water treatment, roads, electrical grid, communications, etc. Unmodified, it refers to any or all of them. We tend not to use the plural to refer to several of them together:
The earthquake severely damaged the city's water-treatment and electrical infrastructure.
We might even see a plural verb after the non-count noun:
They seemed to rest content with the idea that road and rail
infrastructure were now treated on an equal footing... [emphasis mine]
(though this is not from a US publication)
Best Answer
Storage is uncountable. You cannot say a storage. A unit of storage is usually called a store, which is countable, of course. It can also be called a storage unit. For example:
or
(Both in computing and also physical storage, you can use either store or storage unit as you see fit. The former inclines somewhat to talking about storing in abstract, the latter to a physical location. Unit can, less commonly, be substituted with similar words, such as device, locker, location, ....
Edit: This is the situation for British English and US English the situation may be more complex in Australian English, about which I'm not qualified to comment.