If I went to a lot that had a sign at the entrance saying "Open Source Cars, feel free to open the hood and look to learn stuff. No warranty implied. Some may not function. All free to duplicate, free to take parts from, and free to take home", and then took a car from the lot and drove it home, no I would not be surprised if it fell apart before getting out of the lot.
When you purchase a car, you pay actual money, and that adds liability, so if it implodes I feel like I can at least get money back, or sue the vendor for negligence. OSS is not like that. You get something for free and there is a big sign saying "lol have fun", and it's also incredibly well known that software is all buggy and bad with like maybe 3 exceptions.
> If you bought a car and your dealer had you sign an EULA with that sentence in it (pertaining specifically to the security features of your car)
If the security features are implemented in software, like "iOS app unlock", no I would not expect it to actually be secure.
It is well known that while the pure engineering disciplines, those that make cars and planes and boats, mostly know what they're doing... the software engineering industry knows how to produce code that constantly needs updates and still manages to segfault in so much as a strong breeze, even though memory safety has been a well understood problem for longer than most developers have been alive.