If we do not use the energy to mine bitcoin we still use it for another thing to make more money though, and as long it's profitable no matter how much energy it uses there will be no problem at all right?
You are right. It is not only bitcoin wasting the energy, there are other thing that consume energy more than bitcoin. As the digital currency, it is unable to exist if there is no energy, the main power of this digital currency is the energy of electricity.However, it is also unavoidable because it is as the improvement of human creation/technology. as long as it gives much advantages for human life we can not against it. Moreover it helps human finance.