Maybe it wasn’t the first to come up with this kind of idea; I have seen people say things like this that there has been others that were created earlier before we had Bitcoin, but none of them were successful. So, what’s the need of counting them if they were not successful?
Because they did play a role in the success of Bitcoin. I'm quite sure Satoshi must have studied those other projects, understanding them better and decoding the reason behind their failure. Works on bettering them and brought about the birth of bitcoin, the first successful one among them all. Let me make it clearly there's no success story without previous series of failure that was used as a learning stage.
Take ethereum as a perfect example, it was the first of its kind but that isn't the case anymore. Ethereum failure in bringing true decentralized smart contract blockchain which is something the new so called ethereum killers are trying to accomplish but are failing at doing so too. Although that doesn't mean a truely decentralized Ethereum like blockchain (platform) won't be built in the future. When that does happen we still have to give credit to Ethereum just as we have to do with bitcoin processors.