> I cannot understand how anyone treat this as something that can be objectively concluded

Mostly because the room for the unexplained in physics is really small. It's possible that we end up finding some sort of big revelation about quantum physics that completely changes how we view relativity. But even in that case we are more likely to find that relativity is just a simplification of a more complex model with better explanatory power. Very much like how Newtonian physics still works really well from quite small things to anything most humans will deal with on earth. It's only when you start talking about uncommon experiences in extreme environments where relativity starts being a requirements to make the math work.

> there will be no more revolutions, only incremental adjustments on an unshakeable core into infinity

I guess I'm just more comfortable with that position. A lot of the revolutions in science circled around detecting and measure things previously immeasurable and unsee-able. The study of EMF exploded when it did because that's also when our ability to generate and measure electricity in more than just a party trick happened.

We are at a point where things are more of an unknown unknowns with no theoretical way to observe. The physics models at the fringes are mostly centered around things we can't measure.

There just aren't interactions we can't currently predict. The only one I know about is radioactive decay.

And a lot of this shows in modern society. In physics, the last major paradigm shift was relativity. That's a nearly 100 year old model at this point. Everything we have currently is just incremental improvements on the physics model.

I don't think this is because we just aren't as smart today as we once were. Quiet the opposite. There are far more people on the planet. There are almost certainly a lot more "Einsteins" trying to find a new paradigm and they've simply failed over the decades because it's seemingly increasingly unlikely that there is something to find.