Some cryptocurrencies are designed to preserve privacy, to protect people from exactly this problem.
https://eprint.iacr.org/2017/338.pdf
If anyone can debunk this I’d love to hear more, but generally I think it’s dangerous to rely on claims of secrecy
Reasonably private should be good enough for most people.
Even a coin with higher inflation will still be susceptible as a speculative-investment. It would be nice if there was a way to avoid that, and to keep value relatively-stable, but I can't think of anyway that does require trusting 3rd parties.