It seems to me that grammatical number in English is gradually disappearing.
no singular 2nd person pronounce, the "you" becomes limited to one person while "yall" develops for multiple persons (both grammatically plural)
singular "they" etc.
interchangeable use of singular and plural with "I", "me".
"four billion" and alike
"ten foot long" and alike in rising colloquial use
"thanks" as singular
indication of number by only apostrophe in some cases with no pronunciation difference
use of article to indicate number in some cases without morphological change to the words with one of the forms completely becomes unused (two dice - a dice, two billion - a billion etc)
All these things would not be possible in a language with strong grammatical number, thus I suppose the number dies out in English. Am I correct?