Best I can come up with: film statistics as far as box-office grosses were calculated differently back in golden age Hollywood in the studio system. John Barrymore appeared in a lot of MGM pictures, and he spent some years with Warners as well. He was, as the saying goes, a "prestige" attraction; and also, he tended to appear in major motion pictures, if not top billed, prominently billed; in his best years he appeared often in all-star pictures, thus while he could be credited when a film he appeared in made money, occasionally he could be blamed when it didn't. Bottom line: John Barrymore was more a respected film attraction than a box-office draw; and yet many of his movies made decent money, some decent money and then some, while many more just broke even. In this I think his career compares favorably with Meryl Steep's, Robert Duvall's and certainly, from across the Pond, Laurence Olivier. Barrymore's matinee idol days were more on stage, in the theater, and I suspect that's what put him over as a handsome lead and, when at the top of his game professionally, a moneymaking major star.

And although he was still cast in major movies such as Leisen's MIDNIGHT, he was no longer afforded before the title billing.
"The trouble is most people are twats or cunts. Or both."

John Barrymore was also on the infamous Box Office Poison list in 1938.