Global missions, aggregate missions wherein Pokemon players try to complete objectives, have been on a long streak of failures. Pokemon Ultra Sun & Ultra Moon’s first global mission, capturing ten million Pokemon, ended up at just over half the goal.
The two pieces of software have different factors at play, though. Pokemon Go counted every single Pokemon caught, while Global Missions in Ultra Sun & Moon require players to jump through hoops. Trainers who wish to take part have to complete the tutorial for global missions and connect to the Global Mission link, which then allows all Pokemon caught to be counted toward the aggregate total.
So while it’s likely ten million Pokemon were actually caught, not all of them counted.