I agree that saying nature in the past was the same is like saying there were unicorns here. The positive science claim is that nature was the same and so that therefore tree rings represent the same length of time taken for trees to grow now. I will use the historical default position that the record in the bible is true until and unless you can support your positive claims.
The positive science claim is that nature was the same and so that therefore tree rings represent the same length of time taken for trees to grow now.
Missing or extra rings are prevalent in some species, occasional in most species, and very rare in some species. Examples of the latter are bristlecone pines, Douglas fir, and oak. Dendrochronologists use only samples from such trees.
(Speleothems are stalactites and stalagmites. Suigetsu and Cariaco are annually-laid varves on a lake or sea floor. Lisan is uranium-thorium disequilibrium dating of carbonates in a dead sea. New Guinea is uranium-thorium disequilibrium dating of coral. PS 2644 is annual layers in an ice core combined with carbon-14 dating of foraminifera in a deep-sea -bottom core.)
From the same reference, here's a plot covering less time, on which it's esier to se the agreement between tree rings and other methods:
The horizontal axis is years before present as measured by the methods listed in the box. The vertical axis is years before present as measured on the same sample by carbon-14 dating. If all the methods agreed exactly, the data points would lie exactly on the 1:1 line shown. The fact that they don't is useful but the subject for another topic.
But the data points do obviously cluster along a curve slightly below and to the right of the 1:1 line. This clustering is often called "the curves agree".
I tree rings were significantly different in the past, they wouldn't cluster with the other methods. Unless all those other methods are off by the same amount as the tree rings. That would require some major f**king with the fundamental constants of the Universe carefully tuned and coordinated to make all the independent methods off by the same amount, and life as we know it probably couldn't exist in such a Universe.