Yes, bitcoin was not the first crypto or the first decentralized currency, but it was the first successful crypto. Before bitcoin, BitGold and BMoney were the first decentralized cryptocurrencies but both were just theories, they were never fully implemented so they quickly failed.
There are more cryptocurrencies before Bitcoin appearance than just BitGold or Bmoney.
Bitcoin Prehistory Tree.You can see more like Digicash, Cybercash, E-Gold, Hashcash, and BitTorrent.
Exactly but despite of those coins goes first before Bitcoin it manage to became the most successful ever exist on the market. But those who came out first is now can't be found and people is not talking about its existence anymore.
I strongly believe that Bitcoin could hold the lead position in the market since if we look at the adoption level on this coin its still increasing. If we compare the supply of those top alts on the market we can also see that Bitcoin limited supply is more appealing that's why I believe that the other alts will remain alternative and people would continue to buy more Bitcoins.
I also believe that there's no other crypto yet exist that can surpass Bitcoin's popularity. But lets just see what's going to happen in future since somehow everything has a possibilities to happen.