I'd wager you probably have, Rodeo ^.^ At least, if English is your primary language, you'll have used it yourself on countless occasions. It's a common baked in part of our language to the extent that it's more or less invisible unless you're watching for it, but in recent years a lot more people have been drawn to watching for it and seeing it specifically.
'They' as a terms of direct singular reference has been used as a pronoun for unknown, non-specific and/or undefined identity for a very long time; it has always served purpose in our terribly bitsa, cobbled together language for both that and pluralising reference. In more recent years, it's been much more visibly and aggressively used not just for the cases of unknown, undefined or unstated, and has been co-opted into being used as an expressly neuter definite term. We have a neuter definite term already, but, as with many things in English, it's been co-opted to serve multiple purposes, and so it carries with it overtones of non-entity and non-person as well, so naturally a lot of folks absolutely do not want to use it, and they landed on the already overworked 'they' instead.
As a thought experiment, how would you naturally construct a request to someone telling them to, say, get a specific object from a non-specific person matching certain criteria?
Most people would probably construct it something like: "Go find the first person you see wearing a red shirt, get their phone number, and come back." without even thinking about it...
I know this is 'off topic', but the topic is a troll post, so... this is just my chance to share a bit of language chat before the lock ^.^
