I think the tesla analogy is flawed. People want to get between places and the most current methods of transportation emit co2. So, a tesla driver, depending on how the local grid where they charged it is built, will likely emit less co2 getting around than someone driving a combustion powered car. The owner of an electric vehicle is going to want to go places regardless what kind of car they have.

What is the added value that cryptocurrencies have over traditional currencies/speculative investments?

Or what does it mean to 'do cryptocurrencies well'? What is it that we want to do? Their are other mechanisms to invest or to exchange value why are we using all these resources to create 'value' in this way?