The survey you're citing is from before I was born. Things have changed in the intervening 25 years. Pretty much every style guide on the wiki page since ~2010

The survey you're citing is from before I was born. Things have changed in the intervening 25 years. Pretty much every style guide on the wiki page since ~2010 allows or prefers singular they. This includes, as previously mentioned, the APA, the AP, the NYT, WaPo, and a number of other relatively large and formal publications. Perhaps the odd man out is the Chicago Style guide, which says singular they is fine for informal writing, but doesn't yet recommend it for formal writing. While yes, some Baby Boomer linguists may prickle at the singular they, for many in Gen Z, its all they've ever been exposed to, and for many Millenials, they've now used singular they for longer than other forms, in both formal and informal language.