What are some examples of things still in use that have changed little in MANY years?

Actually, modern paperbacks are much less sturdy than earlier printed books.

Wood-pulp paper has a high acid and lignin content, which makes for rapid deterioration, unlike older paper which was made from linen and cotton rags. And glued-in, “perfect” bindings are not nearly as durable as sewed binding.

It’s true to a certain extant.

My college professor had a first edition(autographed) Tristram Shandy. It was in remarkably good shape.

Yes, she was awesome and she let us hold it(it was in multiple volumes).

I’ve got a cold half-lager shandy here in perfect shape.

I’ll let you drink it, if you like.