... And for completeness, the shrinking actually made the tension worse.

Until now with a far better telescope able to significantly improve the sample size, that is.

Ugh, this is so frustrating. We know our current theories cannot be complete but the LHC has mostly just confirmed assumptions, and now this. Everything seems to well contained.

Which is exactly how systematic error would manifest

It would have to be a pretty robust error to survive 30 years of continuous study.

Or a common unchallenged assumption. Orthodox errors are always only obvious in hindsight