Anything kernel level can theoretically modify anything in your TPM too, so Linux programs that use it (admittedly I’m not sure any user program use it) could be manipulated in weird ways

That’s a very old post but yeah, it is, so is Ghidra (a retro-engineering tool). A lot of people have had the exact same argument of “the NSA made it, it has to be evil!” but lots of security people dissected the code (the fact that it was made by the NSA probably made more people look through it in fact) and no backdoor has ever been found in years. It’s safe to use.