It's not a small feat, but they also 4x'd their expenses, which made them lose significantly more. Long term as you mentioned, if they could entirely drop their R&D, which they'll never get to $0, but if they did, they'd still be almost -$2 billion in profit. Business modes can change to help accommodate that at that point theoretically though.
I just don't see them ever getting there. How many years can you lose $20 billion and stay solvent? They'll raise prices like everyone, but they may lose customers offsetting the gains made, or even if they get more, operating costs will go up too. With all of the DCs being built, I also don't see R&D going down anytime soon either.