Plus lounge access - usually of wildly varying quality at outstations on short haul
plus seperate check-in desks - as it should be
plus Fast Track security passes - wildly variable customer experience here
and priority boarding at most airports - front of the zoo isn't always best on short haul unless you NEED locker space
plus more flexibility, plus extra Avios points to use towards other flights and services, plus extra tier points to unlock more benefits the more you fly - rinse and repeat the same beige experience
As for a fully seperate cabin on narrowbodies on short European hops, its not going to happen. That is unless you want to more than double that additional £200 you mentioned and in reality, the vast majority wouldn't.
You're right but all we're doing is demonstrating a failure of the market where competitors can offer the bare minimum that will keep point earning drones (yes, I do mean that) locked in and grateful, even though they know the actual hard product is relatively poor. Competition is meant to make things better, at this point it's a comfortable status quo.