That's way off the mark with regard to purchasing power vs money supply. Check your M2 chart. And your time frame on BTC is too short. Yes, it's trending up, and also becoming less volatile over time.
Not sure what you're disagreeing with. Point is, if I can't predict reasonably well what I'll be able to buy in a few months with the currency I'm using, maybe what I'm using is not meant to be a currency.
> And your time frame on BTC is too short. Yes, it's trending up, and also becoming less volatile over time.
I'm sure I can find a time frame over which BTC is up. Not sure that helps much. It's "trending down" since August 2021. It's "trending up" over the last 10 years. What comes next is anyone's guess.
Regarding volatility, whenever I look at it, all the sources I can find point to some volatility being at least constant over the past few years (I linked a source in another comment which indicates sustained volatility over the last 7 years). I've seen 3 different ones so far. Do you have one that would indicate otherwise?
I could find one[0] but it's pretty bad, it starts with the yearly chart showing that the volatility is not declining, then shows a daily one over 7 days and shows a decline over this period.
[0]: https://medium.com/@silvestrimichela.s/is-btc-volatility-goi...
It's more of an ideal, e.g. the ECB targets this. In practice there's a margin of error, the question is how big it is. Once this error (for the currency you use, e.g. USD I assume, given your comment) and the volatility of BTC are close enough, we can consider BTC as competitive as a currency. Until then it's not.