Ain't history wonderful! So much more interesting than the here and now.
Groundloop: Once price-fixing by IATA was banned Loftleidir lost a lot of their commercial advantage.
I don’t think that’s the interpretation I would put on it. The arrival of the 747 in 1970/71 triggered huge capacity increases on a route-by-route basis as 150-seat 707s, DC-8s and VC10s were replaced by aircraft more than twice their size. All those extra seats had to be filled somehow. Meanwhile markets, particularly Europe-US, were liberalising.
Ridiculous loopholes like Affinity Charters (Join the Batley Rhubarb-Growers’ Association and fly to New York for £99 !) and One-Stop ITs had little credibility, what the airlines wanted was pricing freedom outside the IATA first/economy/excursion straightjacket. So along came APEX and mass-market longhaul travel was born.
IATA only fixed prices inasmuch as bilateral Air Service Agreements made it hard/impossible to offer fares outside the IATA framework. When more liberal bilaterals came along (such as Bermuda II), airlines were much more free to set their own fares. It wouldn’t surprise me if IATA are still setting F/Y/YE fares in those markets where they are legally allowed to do so, but these fares are pretty irrelevant in this day and age, except for calculating the prorates on interline journeys.