To summarize it all on why BTC is king are some of the following key factors which I think are very critical on its success:

1. BTC is a pioneer cryptocurrency.
2. BTC gained early adoption and mass awareness and utilization.
3. BTC has more secure network and algorithm.
4. BTC has limited supply and its price trajectory is consistent with its supply and demand.
5. BTC is continually gaining wide adoption and mass distribution worldwide.