You get systems which use DME/DME then VOR/DME VOR/VOR and then only then will they use GPS raw.
All the GNS family do it this way. Alot of commercial system don't have GPS as the primary but use DME/DME as the primary.
So soaring is completely correct.
As much as peter doesn't like to admit most IFR flights don't reference GPS commercially which is why there is no drive to get GPS approaches.