> b) a risky speculative investment on something that's correlated with the price of CPUs, graphics cards, and electricity, and is prone to major supply shocks
You're exposing an understandable lack of familiarity with recent history when you make such statements. Bitcoin mining hasn't been dependent on CPUs or gpus for a very long time. ASICs (Application Specific Integrated Circuits) dominate bitcoin mining to the extent that it's long been unprofitable to bother using a GPU.[0]
But even if we assume that bitcoin's price is correlated with the price of CPUs and electricity, what is the nature of the correlation?
Naively assuming an ill-defined correlation, we would nonetheless expect bitcoin's value proposition to be deflationary, as all technology is, that is bitcoin makes cost of securely holding and transferring value cheaper as technology continues to improve, which would increase the value of bitcoin, not reduce it. That is, while fiat currency is subject to debasement (money printing makes you lose money the longer you hold it), bitcoin is not. So the value and utility of bitcoin increases, yet the supply of bitcoin is constant. Supply and demand easily implies price increase.
Right now, holding cash is a very costly activity, which is why everyone is constantly looking for investment opportunities. Bitcoin fixes that and becomes even better at, and more suited to, fixing that as technology improves.
> and electricity
Bitcoin dominance as money actually improves the security, efficiency, and competitiveness of energy production. Recall that once upon a time, countries that could produce energy cheaply couldn't export it because transporting energy long distances is expensive and in some cases impossible. Instead, they used their surplus energy to process aluminium[2]. They then exported the processed aluminium. Aluminium served as a means of exporting energy!
It's the same with Bitcoin. Reliance on a bitcoin standard forces energy producers to compete for efficiency and reliability of energy supply in order to secure the bitcoin network and guarantee their own profitability.(Goodbye to blackouts due to incompetence?[3][4])
In places where energy that is produced can't be stored or exported it has to be burned (e.g. in oil fields through flaring) Bitcoin mining can make use of the otherwise wasted energy and thus improve the efficiency of energy production.[1] This will also plausibly lead to profitable energy production/extraction with new technologies in places that might otherwise be too remote to be useful but that can connect to the bitcoin network via satellite. (undersea hydrothermal vents? volcanoes? the sahara?) Hypothetical, but the potential is massive and exciting. Bitcoin gives us reason to be optimistic about humanity's energy production and consumption.
[0]: https://download.wpsoftware.net/bitcoin/asic-faq.pdf
[1]: https://newmoneyreview.com/index.php/2019/10/18/peter-thiels...
[2]: https://cordis.europa.eu/article/id/19086-ambitious-plans-fo...
[3]: https://www.latimes.com/environment/story/2020-10-06/califor...
[4]: https://www.bloomberg.com/news/articles/2020-09-02/eskom-ext...