I agree it's still mostly a speculative investment, but 1 USD has been less valuable than 1 BTC since 2011. Even if you want to use a different formula than a simple 1:1 comparison, there isn't any question that the buying power of the dollar has dropped drastically in that time and the buying power of BTC has majorly increased. USD is less valuable than BTC by pretty much any definition you want to use, and it honestly isn't very close.
The "trustable" question is a little more difficult, but if we use the same pattern we've since 2011 we can trust that two things will happen: USD will continue to lose value, and BTC will continue to gain value. So in that way it's trustable too.
The reason I think BTC still kind of qualifies as a speculative investment is because of its volatility. If that's what you mean by trustable, I agree with you there. BTC is obviously way more volatile than USD, and that probably won't change in the near future. That said, the combination of volatility and a steadily (and significantly) increasing value is what has made BTC such a lucrative investment. Volatility is how traders make money, after all.
The steady increase in value combined with the durability and fidelity of the asset by way of things like blockchain tech, the halving process, immutability, etc., is what makes BTC a great store of value. Don't get me wrong- it isn't a perfect or totally risk-free asset, but then again what is?