Per the Authors Guild, their Author Income survey is "the most comprehensive study of its kind in the U.S. to date." For the 2023 survey, the Authors Guild surveyed: "Thirty-six other organizations, including Penguin Random House, Hachette Book Group, Ingram, B&N Press, PEN America, African American Literature Book Club [...] and 5,699 published authors."
Per the 2023 Author Income survey: "[...] the median book income (including advances, royalties, and fees from licensing and subsidiary rights) for full-time authors in 2022 was $10,000 [...]"
Therefore, per the Authors Guild, in 2023, 50% of full-time writers earned less than $10,000, while 50% earned more than $10,000.
I won't share on what side of the median I fall on, but I do suspect that "full-time" is hyperbolic, because I suspect that, unlike Harry Lesser, most writers can't write full-time on a $10,000 income - especially if they live in The Big Apple.