This flag was enabled by default a year ago exactly and is ripe for removal.
Pull request: https://github.com/WebKit/WebKit/pull/20979
Committed 271195@main (ddee4b2c44f7): <https://commits.webkit.org/271195@main> Reviewed commits have been landed. Closing PR #20979 and removing active labels.
<rdar://problem/118872349>