If you search for it,
you'll realize that there isn't a standard definition for the “global adoption”. Bitcoiners tend to use it in their sentences as a way to describe Bitcoin's adoption by everyone on every part of the planet,
hence “global”.
Listen, dollar is not used globally by all people, but it is, or at least it was recognized as asset for global trading and online payment, even if everyone knows it is backed by nothing and has unlimited supply but it had global adoption.
Gold is also adopted globally and many people are wearing gold on their bodies as yewerely yet almost nobody today is using gold purchasing any items.
Global adoption for bitcoin does not mean that every human being on planet will use Bitcoin all the time, but it can be used as backup asset for trading between countries and for larger transfers all around the world.
If we are talking about using Bitcoin for everyday small purchases than that is only possible with some second layer solution, but I really don't consider this to be a global adoption.