Security has a range of meanings, including the concept of the social safety net, as in social security. There is rarely any reason to treat it as a countable noun, unless it refers to a financial asset, in which case it is more often seen in the plural, securities i.e. stocks, bonds, futures etc.
In theory you could have social securities, but it sounds like some kind of novel currency or investment scheme.
I wish the US would have social securities rather than social security; perhaps then I’d actually have real money when I retire instead of hoping the current Ponzi scheme doesn’t completely break down before I can get my 10 cents on the dollar.
