If you are talking about 'premium' + intra-Europe J, on BA and LH, the YES, pax are getting taken for a ride and should expect more.
On my recent flights, the only difference was lounge access (which are nothing to write home about, at out-station lounges), extra luggage and a 'meal' on board, for some 3-4 (if not more) times the price of a vanilla Y seat.