I think one important point to stress, is yes SpaceX advantage is reusability, but even when Falcon 9 was not reusable is was utterly dominating the market and

I think one important point to stress, is yes SpaceX advantage is reusability, but even when Falcon 9 was not reusable is was utterly dominating the market and was far cheaper then anything else. It was developed cheaper with less capital and a smaller team.