Xbox Game Pass might offer a lot to subscribers, but it is still halfway as popular as PlayStation Plus according to a recent report.
As noted by @Zuby_Tech on Twitter, the Xbox Game Pass has around 25 million subscribers (via Microsoft.com).
If we merge the two, we are looking at somewhere around 51 million subscribers, which is more than twice what the Xbox Game Pass has.
The PlayStation Plus, on the other hand, has around 48 million subscribers(via Sony.com), with the PlayStation Now boasting another 3.2 million subscribers.