And I'm currently writing code for a 32bit CPU that was first introduced in 2000. It's not x86 so SSE is irrelevant, but my point is that GCC is routinely used to build millions if not billions of lines of code, they can't just YOLO-deprecate things as if it were a javascript framework.
It's also possible someone may prefer the 80-bit intermediate precision of the x87 registers. I guess.
If your x86 computer was made after the US invaded Iraq, it supports SSE2 instructions.