Well this exact style of SCXRLXRD is kind of its own thing, the extreme screaming and distortion are ridiculous even by modern standards (And I like it for that).

Trap in general, though I dont know the full history super well, is about the lifestyle of "trapping" which as far as I understand it is like the non-bling version of gangsta rap, talking about the lifestyle doing drugs and stealing shit and just getting by in the jungle of poverty.

Like this song for example is about making crack as far as im told

It's"trappin" the same way rock stars represent the "rock" lifestyle, which also was drugs and sex and stuff just a different flavor.

The general sound of trap is just that big drum beat with the huge bass and kick drum, like any Kendrick Lamar or Drake or Lil Pump or basically any major hip hop these days.