So even if you put the same energy in both , the one which offers more functionality at same consumption is more efficient
It may be, but the more information to be processed, the greater the energy consumption.
That is, it will not be the blockchain that will be greener, but the hardware that will have to be able to process more data with the same energy consumption. Blockchain can only promote a greener idea, but it's not the blockchain that deals with energy consumption, it's the hardware.