Open source is about spreading the information and value of software around so that anyone can learn from it, modify it for their own needs, identify and correct mistakes and vulnerabilities, and pass what they've done around again for others to use. It's the very antithesis of central control and limitation.
Trying to control open source software is like trying to pick up a blob of mercury off a mirror with your fingers. Can't be done.
And as far as LLMs, you can go to Hugging Face, and find plenty of Open Source models that aren’t liberally biased.