Bitcoin is the highest market cap cryptocurrency primarily because of its first mover advantage. Bitcoin was the first cryptocurrency that came into existence. It's got the most powerful network effect in place. Because of its age, its user community is the largest. Secondly, while Bitcoin scales poorly without second-tier solutions, it is also proven to be the most secure one. Bitcoin has the largest amount of hashing power of all cryptocurrencies. What this means that taking control of the network and falsifying the record is extremely expensive. Even in its present form and without any second-tier networks to help it scale, Bitcoin is suitable for transferring large sums of money because of its security. And it's still cheaper to transfer a million dollars to another country using Bitcoin than via wire transfer.
What do I mean by a second-tier solution? I'm talking about the Lightning network. The lightning network is a network on top of the Bitcoin blockchain where payment channels are opened between Bitcoin addresses using smart contracts. When a channel is opened, a number of bitcoins is are locked in a contract after which extremely fast transfer of bitcoins between the addresses can take place. When a channel is closed at the end, only one transaction on the blockchain is created, equal to the sum of the transfers in the channel. On the Lightning network, networks of channels can be created enabling micropayments to be processed extremely fast over the entire Bitcoin network. The only drawback is that opening the channels requires capital to prevent double spending and make the channel secure for both parties. The Lightning Network is currently under development and testing.
Here's additional information on the Lightning Network: https://lightning.network/
Bitcoin benefits several bonuses:
* Bitcoin was first mover
* Bitcoin is technically very sound
* While Bitcoin isn’t fully decentralized, it benefits a large network
* Bitcoin has a decent network of developers, and when one leaves (for a new forked token), they are quickly replaced in the meritocracy. Often with just as good or even better leaders
* Billions of dollars have been invested in mining and the estimated production cost is currently higher than the actual rate of BTC, which means that the top miners who have invested multiple millions in both hardware and infrastructure are willing to take a loss just to see others drop out. The race for position is brutal
* Bitcoin has survived multiple forks and is still the leading token, which is a massive trust factor
* Bitcoin has received, and still does, most coverage from mainstream outlets.
Forked tokens like BCH, while cheaper and faster, aren’t that much faster. As least not as fast as their marketing makes it sound. And Bitcoin transactions currently are barely more expensive (but yes, many exchanges still charge higher network fees).
Lastly, Bitcoin is a base layer blockchain and many efforts, like Lightning, are made to speed the the network up. Just like with Ethereum there is no doubt that Bitcoin can scale and operate much faster if they want to make it happen.
First, bitcoin has been one of the most vetted cryptocurrencies. Whenever bitcoin gets "hacked" it is virtually always due to human error in not keeping a private key secure. When other cryptocurrencies try to use their own code there are sometimes vulnerabilities that allow a direct attack. This gives bitcoin the perceived value of being extremely secure.
It's also a combination of basic brand recognition and scarcity. Bitcoin and cryptocurrency are synonymous in most people's minds. It's also a status symbol to own at least one bitcoin. Most countries have a population over 21 million so if as an example everyone in Canada wanted to own one bitcoin each even after the last bitcoin had been mined that wouldn't be possible.
Of course, if the world switched over to bitcoin the source code would have to be modified so that there would be more decimal places and transactions could be made with less than 0.00000001 BTC.
It stays dominant because of how well known it is and it is the basic buy in coin from fiat. You pretty much have to buy bitcoin in order to exchange fiat to any other trading pair.
It is liquid gold , that's why , gold isn't easy to use buy coffee either so it's mostly a store of value ( so is Bitcoin).