Space

I think you're understating things. The measurements don't have to be 100 km/s/Mpc apart to cause problems for our understanding of the universe. Ruling out measurement error means we have to go back to the drawing board on cosmology. The problem isn't sloppy telescopes or anything -- it's definitely a hole in our current model.

If they wanted to use the term "deeply wrong discrepancy", maybe they should have gone with the difference between the universe's expansion predicted by quantum vacuum energy and the actual, much slower observed rate of expansion.
By "much slower", I mean that the theory and the observations differ by something like one hundred and twenty five (!!!) orders of magnitude.

I think the deeply wrong part of it is that the difference is now big enough for the error bars to stop overlapping

Maybe the light does a detour before it reaches the telescopes.

Lerner is a massive kook and scam artist

If you're interested in this stuff, Thomas Kuhn's The Structure of Scientific Revolutions describes a lot of how science actually happens, where most normal science builds up accumulated information under an accepted paradigm, but occasionally those old models slowly become untenable with repeated observations that are anomalous or not explained by that existing accepted scientific paradigm. Then a scientific revolution occurs, the old paradigm is cast aside or limited in its scope, while the new paradigm takes over as the generally accepted set of theories. The book is one of the most cited works of the post-war era.

~~Geocentrism~~ Heliocentrism didn't have a clear advantage over ~~Heliocentrism~~ geocentrism, until Kepler made the observation that the planetary orbits were elliptical. (One big objection to geocentrism was that the stars should have some kind of observable parallax if the earth were moving around the sun, but that ended up being explained by learning just how freaking far away the stars are.) Heliocentrism with elliptical orbits, though, laid the groundwork for Newton's theory of gravitation.

Later on, Mercury's anomalous orbit just couldn't be made to fit Newton's theory, but astronomers held onto Newton's theories for decades before Einstein's general relativity was enough to explain it. Einstein's own cosmological theories needed to be fit in with the discovery of the cosmic background radiation and our expanding universe, and eventually we got to our current paradigm of the lambda-CDM model, which postulates the existence of dark matter to account for galactic structures, dark energy to account for the acceleration of the expansion of the universe. All along the way, there were discarded theories that just don't hold up.

The history of how we got here can help inform how we should speculate about where we might go next. New normal science might try to figure out what dark matter actually is (different theories can be tested by looking for different observations), without actually challenging the overarching lambda-CDM model. Or research into the Hubble Tension might allow enough observation to propose a new model entirely, for a revolution into a new paradigm.

And of course, Kuhn wrote his hugely influential book in 1962, so many decades of thought have refined and challenged some of those ideas. It's interesting stuff.

But how could light pass through nothing? Surely there must exist a lumeniferous aether!

I mean, the recent discoveries actually do not dispute most of the previous theories. Most of the time the old theories are fringe cases where some parameters are simplified so you get the new theory that is actually a general case of the classical one. It's not like our old formulas stop working when we discover new cases...

I could've sworn there was a thought experiment for an omnipotent being modifying the universe but only when we are intentionally trying to study it, but this is all I could find. https://en.wikipedia.org/wiki/Evil_demon

This concept is stuck in my mind as "Cartesian demon" but that only leads to the above which is more about the idea that we could be in a simulated reality. It's possible I'm getting an xkcd comic mixed in but I couldn't find it either based on a quick search.

Edit: The comic was something like a sliding scale (or maybe a flow chart) of different views of reality. On one end was everything is fake, even self, and the other end was that everything is real and measureable. Somewhere in the middle was the idea that reality exists but we can't measure it properly or objectively. Something like that. But it's also possible this comic was unrelated to whatever I'm remembering as "Cartesian demon" and I'm getting mixed up.

To be fair, there’s always been something deeply wrong with how most people understand ~~the universe~~.

FTFY

I was a bit confused too as I was pretty sure this was old news. Here's a NASA article from 2023 with more information.