Your IDE should help you with the argument order if that's an issue for you. It has never been a problem for me and I don't understand the argument. I get that it might be confusing the few first times you use these functions, but if you use them every day you just remember the argument order.

The backward compatibility section found only 200-ish projects where array_find() was defined in global name space. For me that's a small price to pay for introducing the new function, and refactoring should BE easy when upgrading a project to PHP 8.4.

Adding array_find() to a namespace would be inconsistent. All other array_*() functions are global.