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.
To be fair, it is difficult to see the real reason why XMR or ZCASH cannot become popular even though they are completely superior to bitcoin in terms of privacy and anonymity.
People don't actually care about privacy and anonymity, and there is regulatory risk against privacy coins like Monero. Like you can ask many Bitcoin users whether they care about privacy or anonymity and why they invested in Bitcoin or used Bitcoin blockchain, most of them will give you answers without anything related to privacy and anonymity, even decentralization.