> The minimum evidence that we are in fact in a simulation would be observing a violation of physics.

Not at all. A "violation of physics", by which I assume you mean a discrepancy between our picture of the universe and the real universe as revealed in experiment, only tells us that our model is wrong.

There have been any number of "violations of physics" over the decades. We believed that a luminiferous ether served as a medium for light waves -- wrong. We believed that neutrinos didn't have mass -- wrong. We believed that all mass/energy was accounted for by the descriptions in the Standard Model -- very wrong (only 4% is so described, the rest is dark matter and dark energy, with no present explanation).

The simplest explanation for these discrepancies, consistent with lex parsimoniae or "Occam's razor" is that our model isn't good enough and needs revision, not that the universe is a simulation.

It's equally logical (and not very logical at all) to argue that a perfectly running universe, with no anomalies, would constitute evidence for a simulation, on the ground that any self-respecting superbeing able to craft an entire universe, would surely test his code before launching it.

When someone posts something like this, do they honestly believe everyone else having this debate, including serious physicists, are just stupid because they can't see the brilliant insight they have posted?

It would be a leap of logic to assert that we're in a simulation after observing a violation of physics. The first possibility we'd have to consider is that our understanding of physics is flawed. After that consideration (or maybe as a part of that consideration, depending on how you look at it), we'd have to consider the possibility that the laws of physics are not constant.

But why would we jump immediately to the universe being a simulation?

It is not possible to observe a violation of physics, because physics is defined as whatever you observe. For real.

that doesn't really make any sense though