There are many reasons.
- First ever crypto currency
- Anonymous
- Decentralized
- Fast and secure
- One click payment sent.
- Great profits
- Known by almost everyone.
- Better then gold
- No age restrictions
- Free to use
- Easy to earn
- Easy to use
It is a great investment and many users are coming towards it every day and it is getting popular. The reasons are mentioned above.
I doubt the las 3 points
Free to use? What is the meaning of free? Trading? Mining? You eed capital for it or you mean bounty? Then yeah it is
Easy to earn? I barely have 1 full btc LOL
Easy to use? For you and most of us here yes, but for average person not really. Blockchain is quite complicated for non tech newbies
Many of the features listed are actually shared by other cryptocurrencies, so they are not unique to Bitcoin. The question is why is Bitcoin specifically more popular. Bitcoin is the first and most popular cryptocurrency. Most people don't even know about other cryptocurrencies and think Bitcoin is what the whole cryptocurrencies thing is. Obviously, it has huge brand recognition.
But These things don't mean that Bitcoin can't be surpassed though. If you look at market capitalization, until the beginning of the previous year, Bitcoin was like 95% of the entire market. But since then other ones, especially Etherium has been gaining market share. There was actually a time during the middle of the previous year when the market cap of Bitcoin and Etherium got kind of close.
I think that another cryptocurrency can become more popular than Bitcoin if it has some innovative new features. These can be about ease of use, better security features, or even something like lower power consumption (mining) because then it would be touted as being part of a green economy and would attract attention from environmentalists.
For example, another cryptocurrency that has been gaining great popularity very recently is Ripple. It has some innovative new features, and so much so that some analysts are saying that it should even be considered a cryptocurrency in the way that Bitcoin is.