"Avengers: Endgame" is now the highest-grossing film of all time, topping "Avatar."

There's a reason the film industry doesn't measure the success of modern movies against those of the past — movie ticket inflation isn't an exact science.

Notably, the number of options of what movie to see in theaters is so much larger than 50 years ago.

As "Avengers: Endgame" has raced its way to and beyond the highest-grossing film record held by "Avatar," questions have arisen about how Hollywood determines what movie is considered the biggest earner.

After all, "Avatar" was released in 2009, so wouldn't a fairer comparison between the 2019-released "Endgame" be adjusted for inflation?

Well, it's not that simple.

There's a reason the film industry doesn't measure the success of modern movies against those of the past — movie ticket inflation isn't an exact science. There are so many factors behind what makes a movie a box office success and those factors have changed since the earliest days of cinema.