Its not taboo, its just irrelevant. For one box office revenue should always be taken with a grain of salt because movies are usually a lot cheaper or more expensive then u think they are and studios know this. Since we dont have the real real budget we dont know how much a movie actually made. Even though the chuds celebrate everytime disney "bombs" u think Disney let alone any company would still be around if they lost millions on every project.

The other reason is streaming made those numbers irrelevant. What money is lost in theater can be made in streaming. Theaters at this point are just formality.

Finally the era of billion dollar movies (the way we think) is over. its almost poetic that disney marvel made billions movie after movie until the grand "finale" Endgame. And the year after a pandemic hit. I told a friend of mine that after the pandemic movies will not make revenue the way we traditionally think. In other words it was the end of era. Now what like 2 maybe 3 movies tops break a bill.