BA claim to operate their own lounges at over 20 international destinations. Getting into one of those using non-BA oneworld status if flying on another oneworld airline is like winning the lottery - it's never happened for me. CX, JL, QF, AY, MH, IB, no problem. But I wouldn't put BA towards the top of the oneworld lounges happy family tree. And even with BA the direction of travel appears to be to close their own lounges and shift to third parties, with access only for their own passengers.

Yes QR protect premium travel in their very much smaller international network of lounges (only 4 locations outside of DOH), and choosing to book a P class ticket comes with its own well publicised restrictions. But their own passengers do always get a lounge based on oneworld status, even if it is a third party offering, just like BA.

I know people like to compare and contrast QR with BA, but I'm not sure they're really all that different in this instance