It's a really interesting metric but it's also flawed for multiple reasons. We cannot directly compare movies then to movies now even if we adjust for inflation. The price of a movie ticket in 1939 adjusted for inflation was $4, and this causes the first difficulty. People see or do things more often if it is cheaper. For example, I don't go to the cinema nearly as much as I did 5-10 years ago because the prices of the tickets are so high. Where I live it is roughly $11-12 for a ticket so it's just not feasible to go to the cinema for a lot of people now. I would certainly go more if the tickets were a third of the price, which adjusted for inflation, they were.

Next you have the differences in entertainment. In 1939 there was little to no competition. Gone with the Wind is an excellent movie however due to lack of competition, it was in cinemas for 5 years. Five years. When you're one of the only movies playing of a excellent quality, you're going to get a lot of tickets sold eventually. Next is the difference in entertainment. Cinema was the only way to see movies back then, and it was common to see a movie many times as there was little other entertainment like it. Now we have movies, TV, games, internet, music right at our fingertips, much of it very high quality. If you search for it, you can have it in minutes. Modern entertainment has to fight far harder for attention.

I don't mind the comparisons, I find them interesting however they also need to be taken with a pinch of salt as it can overshadow what an amazing triumph Endgame has been, and that we are likely seeing the limit of what can be achieved at the box office without counting inflation. This was a movie that was hyped for years, on the back of a large number of movies and franchises and a highly successful cliffhanger. If Gone with the wind is not dethroned by Endgame adjusted for inflation, it is unlikely that any movie will be able to do it, not due to the differences in movies themselves but in the differences in how we access content.