Granted, 250m less than 1.2 billion... is still damn near a billion. Remember, prior to the MCU, Spider-Man movies (Garfield) were rounding out at 700 million. We also have 16 years of Wolverine and X-Men movies that, until Deadpool, were doing less than MCU Ant Man numbers as an IP.this movie was so quick i never even had a chance to think, "ewww, they're all women!!" it looked like a marvel movie. there was not a single thing about it that was even "girl power rah rah." it flopped b.c the mcu is pig slop right now. Captain Marvel 2 would have made $250 mil less than the first one even if the MCU was still cooking and all the tentpoles were cracking a bil. it was the most inflated movie financially in the entire mcu
Point is, the MCU (and DCEU initially) were lightning in a bottle pop culture phenomena that could make mid/unknown IPs (Ironman, BP, GotG, Sucide Squad) bigger box office hits (if executed correctly) than the previously "unquestioned" triumvirate of Superman, Batman, and Spider-man.
But the execution is where DC failed years ago.. and now Marvel finds themselves in that territory. i.e. the difference between 2016 Suicide Squad (745m BO) and 2021 The Suicide Squad (168m BO) is the public perception of the DCEU brand in those 5 years. Now we're seeing that in Captain Marvel. They had a blank slate to make a female "superman in space" IP, and fumbled.