Avalanche was released by Ava Labs in September 21, 2020 as a low-cost, fast, and eco-friendly smart contract, AVAX is the native token of Avalanche, which become popular just after its release.
Popularity:- Cryptocurrencies and smart contracts started on a large scale in early 2020, when people around the world were settling for work-from-home and online income due to Corona pandemic. Avalanche's native token AVAX was successful in making something different in this crowd, it immediately started gaining popularity.
Passive Earning:- One of the reasons that made AVAX popular is its feature to reward the HODLer (holder). AVAX HODLer can stake their AVAX by running the Avalanche node and earn passive income. However, this needs 2000 AVAX, but people can stake low amount of AVAX in 3rd Parties like Binance.
Comparing with Bitcoin:- For few months, AVAX performed as a reverse of bitcoin. Whenever bitcoin went down in the market, AVAX went up, and when BTC went up, AVAX went down. This gave popularity to trading BTC/AVAX. Gradually the performance of Avalanche (AVAX) also started changing, it started performing on its own instead of reverse path of BTC.

Year 2022 has just started, AVAX is riding on $100 level Bull, it might bring new performance.