I am made scarce,
Yet overly common.
Plenty are dying for I am sparse,
Yet I'm concurrently not rarely in excess to some,
Many of which the support from the deprived overspill.
For me, some kill
My forms are dynamic and practically endless,
With varying degrees of universality and applications, more or less.
Nevertheless, I equally serve anyone in whatever situation I find myself in,
While I rule everybody and everything.
What then am I?
While straining your brain, please do not die!
A/N: Yeah, I know it's not a difficult one to crack. Fun fact though. The letters that make up the answer are in the name of the poem, just pick them out, they're already in order.