Bitcoin can be cloned the same way Facebook can be cloned. You could spend a billion dollars copying Facebook's features and spend a billion marketing it, and y

Bitcoin can be cloned the same way Facebook can be cloned. You could spend a billion dollars copying Facebook's features and spend a billion marketing it, and you'd still fail. The mining network behind it, the developer ecosystem working on wallets/libraries/services, etc. is the hard part to copy. It's worth the most, therefore it attracts the most time and attention, which helps to maintain its value. It may not be the best from a technical standpoint, but the size of it ensures a healthy financial incentive to improve upon it, which we're seeing now with layered scaling efforts (lightning network).