You realize there's regulation other than just banning things, right?

https://www.hhs.gov/sites/default/files/open-source-software-risks-in-the-health-sector-tlpclear.pdf

October 2023: FDA finalizes guidance mandating that all medical devices running software must create and maintain a software bill of materials (SBOM), including for open-source software.

Still, the point being is that to develop Open Source medical software, you're going to be dealing with potential regulations that you must pass to be able to legally release the software in places like the USA (you can always host the files in some country that doesn't give a shit). Achieving meeting the regulation can often drastically increase the cost of development. Open Source projects can't just magic up more money for development like giant corporations can.

Look in 2024 we're barely cracking 5% of people in the world using Linux as a desktop. The FDA doesn't have to ban it to make "normal" people scared of using Open Source solutions. It's a harder hill to climb than just getting people to change their desktop OS.