Earlier quoted context omitted.
I'm disappointed, but not surprised in your measurement of success. Many tout record box office takings as clear success but I rather think that really reflects on inflation (both real and artificial). Look at admissions over time. I only have UK numbers to hand [1] but despite an increasing population, we're still at barely a tenth of our 1950 numbers. MPAA stats [2] seem to show the US in decline over the last few…
From the data in your link [1] Cinema attendance looks very healthy, and in fact in 2018 was at it's highest level since 1971 and is more than tripple it's low point in 1984. That much better than I was expecting and frankly in my eyes kills the 'Cinema is dying' meme stone dead. I don't understand how you can be looking at the same table and coming to such a different conclusion.
If you're going to make qualitative claims, where the price of a unit is largely fixed at a point in time, I think you have to compare quantity of sales, not gross.
It's all marketing wank. A way for producers to pomp around with their "record"-breaking titles. And at a financial level, sure, whatever... But that's not how these statements are used.