That is based on the assumption that we know everything about physics. I don't think that is the case.
It wasn't that long ago that the "sound barrier" was just that: a barrier.
You need to leave some "wiggle room" for things that are presently unknown to us. Perhaps those from out there have made a few discoveries we haven't. Thousands of credible people have seen these things. It is far more prudent to suppose that there is something we don't know rather than assume all of those people are in error.
“It wasn’t that long ago that the “sound barrier” was just that: a barrier.”
The sound barrier had nothing to do with physics, it was just a barrier some people thought, without any evidence, was unbreakable.
Physics is what governs our universe. Clearly, there are things about physics we don’t yet understand, but the fact is that mass increases as we approach the speed of light. This law was discovered by Einstein and has already been proven to be correct. No one yet has defied the laws of physics in any form.