Are 8 pin to 12VHPWR adapters safe?

A few years ago I know power adapters werent to well looked upon,with cables like 2x molex to 6 pin or to 8 pin not being recomended,however,are these ones safe?The 12VHPWR cable is famous for melting even when being straight from the psu,I however have a nonmodular psu with 2x 6+2 pin. Are such adapters safe or is my only option buying a brand new psu?My new gpu doesnt use the new cable but I want to be sure in case i opt for a 9070 xt or 5070 instead