Ariane 5 was to go to standard for expensive geo missions that required high reliability. Arianespace always launched more Soyuz then Ariane 5s.
In the early 2000s the Proton rocket was far cheaper, but increasingly became unreliable meaning that many costumers got away from it. The Proton insurance cost was getting way to big. The Proton program was just all around mismanaged.
Since with the launch monopoly in the US, the US was basically not in the market at all. There simply wasn't another option. If Soyuz was to small, then the Ariane 5 was the only game in town.
Basically the Russian and the US committed suicide by stupidity and the Europeans were the only game in town. China isn't really an option geopolitically. And India and Japan large vehicle have way to low production rates, only being used for domestic stuff.
Falcon 9 was already cheap but it took a while for Falcon 9 to get cadence up. And Falcon 9 was hopelessly overbooked with launches for many years ahead in most of the 2010s. So some costumers picked Ariane 5 as those were actually available.
In the early 2000s the Proton rocket was far cheaper, but increasingly became unreliable meaning that many costumers got away from it. The Proton insurance cost was getting way to big. The Proton program was just all around mismanaged.
Since with the launch monopoly in the US, the US was basically not in the market at all. There simply wasn't another option. If Soyuz was to small, then the Ariane 5 was the only game in town.
Basically the Russian and the US committed suicide by stupidity and the Europeans were the only game in town. China isn't really an option geopolitically. And India and Japan large vehicle have way to low production rates, only being used for domestic stuff.
Falcon 9 was already cheap but it took a while for Falcon 9 to get cadence up. And Falcon 9 was hopelessly overbooked with launches for many years ahead in most of the 2010s. So some costumers picked Ariane 5 as those were actually available.