At one time, including the era dominated by 747-200s and DC-10-30s on long hauls, flights from Europe to Japan were also routed through ANC, due to range limitations and the Soviet Union's refusal to allow flights over their territory. All routings therefore available required at least one stop enroute.
In about 1985-87, the Soviets began allowing a limited number of flights through their airspace over Siberia for fairly substantial fee$ and non-stop Europe-Japan flights were inaugurated. Among the first airlines to begin non-stop service to NRT routed over Siberia (as I recall) were Japan Air Lines, British Airways, Lufthansa, KLM and SAS, with each airline typically flying Europe-Japan non-stop 1-3 times weekly (though ANC or other stop(s) on other days). During the same period, it seems like the Soviets also required some of the same airlines to route at least one weekly NRT flight with a stop at SVO -- with Aeroflot being granted reciprocal rights for 1-stop (also SVO) same plane (IL-62) service between NRT and the hubs of European airlines with overflight rights.
ANC (as well as SVO) almost totally disappeared from the timetables of European and Japanese airlines as a stop on passenger flights between Europe and Japan by the early 1990s when the airspace over Russia (by then the former Soviet Union) was opened for as many non-stop flights as the market would bear, a distance easily handled at full payload by 747 Classics and DC-10-30s, to say nothing of the capababilities of the 747-400s, MD-11s and 767ERs in service by that time.