Powell isn't really one of Trump's "people" or someone he'd want at that position, but Chairman of the Federal Reserve is an extremely powerful position and if Trump were to try to attempt to get rid of him or apply political pressure to make him resign/retire, he'd also be attacking some very powerful and well-vested financial interests and these people are some Trump knows all too well and fears probably. So, Trump will instead play the waiting game and not many significant moves against Federal Reserve or Powell until his current term runs out in June 2026. I realize that isn't one of Trump's strengths as he's increasingly impulsive, and lacks a basic, functioning filter most days, but this he won't fork with because bluntly, they could ruin him if they wanted to or if he started infringing on their territory.
Many of these powerful NYC Wall St. investors, bond and hedge fund owners also probably know potentially damaging information about him that perhaps most Americans or most people in general don't know about and if these sorts of potential charges would stick hard, fast and quickly.