In my understanding it is the very point of Bitcoin that it can't be "mined" more efficiently. Bitcoin relies on complex calculations to maintain its value. There is probably a reason why Bitcoins are mostly mined in counties with authoritarian governments now, as the tolerance of people to see new power stations being built in order to increase the mining of Bitcoins will be limited. However, perhaps you want to volunteer to have a nuclear power station being built in your neighbourhood for that purpose?
As to the energy consumption of the regular financial system, that's a rather ridiculous attempt. So far Bitcoin isn't really more than a niche within a niche.
Finally, whatever your position on spaceflight, at least rockets deliver physical stuff into space, while Bitcoin has to prove that it serves a purpose first.
Actually, per capita more bitcoins are mined in Iceland than anywhere else. I don't think that country quite qualifies as an "authoritarian state". Cheap geothermal (carbon neutral) power, and free air conditioning just by opening a window makes it a no brainer. Also Iceland has very low crime (less risk of server theft). Also, BTC is only one of many different crypto currencies, with more efficient options available. It is reasonable to assume that with time, we will adopt more and more efficient standards. BTC is king now, just like the Model T Ford was a century ago. A different story today
I'd prefer a nuclear power plant in my backyard over a coal/gas power plant any day. I believe in statistics, not fear mongering. The coal power plant is certain to affect your life, the nuclear power plant not so much. However, since I live in a city center, building a power plant of any kind here makes very little sense, it would be wiser in either case to build it where land is more affordable and population is less dense. The facts show solar power kills more people than nuclear ever has per TWH of energy generated, so you can dislike nuclear if you want, but just acknowledge that your viewpoint is not based on evidence, but emotion.
It's ridiculous to ask how many resources the financial system uses today, but totally reasonable to do so for BTC? Again are we arguing using facts or emotions here? If it's a debate of emotion, count me out, sounds like a waste of time. Lets talk numbers or not at all. You can adjust per market cap, of course. I am not saying that you shouldn't, but you can't do that until you know both figures.
I believe 100% that colonizing Mars is necessary and believe in SpaceX's mission. However, if you scream and cry about how much Elon is polluting for doing a single BTC transaction, yet cheer when rockets lift off, perhaps question that. Again looking at the numbers of CO2 generated, one Falcon Heavy launch is a heck of a lot more than a BTC transaction. Your statement that BTC serves no purpose is clearly incorrect. BTC is a great value store to protect your assets from inflation as governments print money to essentially steal your life savings unnoticeably. Tesla's crypto investment is a hedge against the current money printing going on. As someone from Germany, you should understand better than anyone how exactly money printing can destroy savings very rapidly.
That $1.5 billion stored in BTC could give Tesla a
huge edge if inflation increases post-covid. Almost every economist is saying inflation will get worse in the near future, and that just makes sense. Most of the G20 are busy trying to print their way out of this problem to fund stimulus packages. My country (Canada) has been one of the worst offenders in this case. Hence why I moved more of my portfolio to BTC last year. If you were living in the Weimar Republic when the money printing started, and you had the option to either keep your assets in Marks or move them into BTC, what would you have chosen? Would you leave $1.5 billion in Marks in the name of reducing CO2 emissions? Looking back it would be an easy choice and many Germans did try to secure their money in foreign currencies. However, with a global pandemic, that won't work as well, so we need modern solutions.
There is a good saying "those who don't learn from history are doomed to repeat it".