I did an interview on data in the book The Next Mormons that indicates only 50% of Millennial LDS believe the Book of Mormon is actual history.
Even more surprising, as we discuss in the video, is the data that only 62% of the Boomer/Silent generations are "confident that the Book of Mormon is a literal, historical account."
This data seems to reflect the warning from Joseph Fielding Smith that M2C would cause Latter-day Saints to "become confused and disturbed in their faith." If anything, that was an understatement.
Now, in 2024, after decades of promoting M2C, the M2C scholars have persuaded many Latter-day Saints--perhaps a majority--that Joseph Smith and Oliver Cowdery misled everyone about both the origin and the setting of the Book of Mormon. They've rejected both the New York Cumorah (by adopting M2C, the Mesoamerican/two-Cumorahs theory) and the translation by means of the Urim and Thummim that came with the plates (by adopting SITH, the stone-in-the-hat narrative).
I've heard both praise and criticism of the study methodology used in The Next Mormons. Anecdotally, though, the data seems about right.
And, naturally, the Grievance Grifters on the Internet, such as Mormon Stories, who seek to undermine the faith of the Latter-day Saints, love using both M2C and SITH.
I discussed the problem and offered a solution on the no more contention blog, here: