Hi,

Im new to trading, there are so many coins and I keep reading about bitcoin being unsustainable regarding energy it uses to mine and there are coins coming out with faster transactions time.

If this is the case, Why is bitcoin considered the main one and its price not crashing from the threat of these other more equipped coins? Is bitcoin still able to develop and evolve and become energy sustainable and compete with faster transaction times if it is decentralized? No one is able to improve it?