A good read: https://bitcoinmagazine.com/culture/what-makes-bitcoin-different-from-crypto

Long story short, BTC is different as:

1. Bitcoin is a leaderless system of rules, not rulers
2. Bitcoin Is actually decentralized (unlike many which just "look decentralized")
3. Bitcoin Is censorship-resistant (like even if the government legally bans it, you can still use btc)
4. Bitcoin Is seizure resistant (this is if you keep your pkey safe!)
5. Bitcoin had a fair launch
6. Bitcoin is issued based on proof-of-work (crypto like eth are based on proof-of-stake)
7. Bitcoin is scarce

Hope that helps :)