You're right about this, there have been several encounters whereby people in the past have made attempts towards creating a digital currency and they all die along the way for some other reasons, there have been various contributions and research developments works that many of these developers have made and everything happened to be limited on only the testing stage, but the moment Satoshi tried his own project and take time to work on where others have stopped, fix their lapses and consider the masses and the economic needs of the people with their finances, he work rigorously along with other cypherpunks like Hal Finney and developed bitcoin, then release it by first running a test on making the first transaction to Hal of blessed memory before things began to expand about bitcoin and its demand/widespread to bitcoin pizza, and now here we are again with it, everyone is interested and excited for adopting bitcoin in serving them many purpose as they want.