It seems like the options are 1) MicroPython, which is really easy to use (use python for everything) but lacking in anything lower level to a quick restriction on what you can do. 2) C, which I've used before and understand, but going from the Arduino or PlatformIO experience would require a lot of learning as well. 3) Rust (with embedded_hal and embassy), which is newer, along with different language, but with ability to go lower level with complies, and seeming overall goal to be more widely used.

College was all C/C++ so I've used that before, so I can understand and pick up the code. Since I have brief experience rather than your experience, I'm betting that the time it'd take for me to get up to speed with C and fuller dev environments would take as long as with Rust, and since I can use rust in more applications for what I do professionally, I'm figuring to put the time there.

What have you built and with what in your 25 years? Too many posts and vids about these things are intro rather than more in depth. It's great to hear from people who actually do this into production rather than mini-projects.