I find it weird how unserious manufacturing companies are about dogfooding. This is like Larry Ellison saying 'Yeah we actually think Postgres is better so we use it internally but feel free to buy our database if you want, just not my preference' it's unthinkable. Tim Cook wearing Meta Quest...
On the other hand, to continue your example scenario, if Tim Cook were to show up to a meeting wearing a Quest 3, you can bet that would get the attention of every Apple employee who is even remotely involved with the Vision department. If the CEO wants to use a competitor's product, that is a powerful signal that you should be fixing your own product.
In 1980, IBM salesmen would walk into a wall-to-wall big blue client and see all the execs running VisiCalc on Apple IIs. Cue the gnashing of teeth.