If it works the reward is huge since the stopover carriers can't respond and it's not like European carriers are going to be rushing into the market.
The stopover carriers (do you mean the ME3, TK, SQ?) certainly can respond with a very attractive soft product and pricing, for a particular segment of the market that
prefers a stopover or a transit, especially without the premium QF will be charging.
Personally, it isn't the length of the flight that determines my very long haul Vs stopover/transit choice and its not one or the other.
Very long haul Pacific
I did DFW-SYD last January because 1) it was part of an AY RTW and 2) Hawaii or Fiji simply don't appeal as stopover or transit points. I did do SCL-IPC-PPT-AKL once, but that's another story. And when I was shuttling across the Pacific for work, I used OW 'Circle Pacific' fare, where it was straight across to LAX-YYC and return YVR-NRT or -HKG (overnight) then onto home. More fun, and cheaper, including hotel, so client didn't mind.
Very long haul Europe
Singapore & Istanbul on the other hand I can spend a few days in anytime; ME ports less so, but OK and over-night certainly. Plus the carriers offer special fares to stop-over, so that works for me. The airports are mostly excellent for transits too, if needs be.
As for the Europeans, AY ad LH already offer great fares through to Europe originating their metal in Asia and using QF to connect through to those. They might sharpen that price/service and people can still earn QFF points

.
I am sure Sunrise will succeed and be very profitable for Qantas carrying those businessmen and others who are OK paying a premium for saving 3-4 hours

to London (only, CDG probably next). No advantage at all if the final destination is any other European port, so the continental European airlines, won't be too fussed at all as pax originating in Australia will still get there with 2 stops, (like Sunrise pax) and probably quicker.
Anyway, good choices coming up and long may it continue.