Peak means when a particular game’s population is highest.
Games with stronger international audiences on pc peak in earlier hours of the day if you live on the east coast of the states. This where Helldivers 2 in particular is most played as well as Apex for instance.
Apex is a crazy example. Peaks above 200k everyday in the early morning, but during North American peak gaming hours it holds like 70k.
With that said, I rarely see the territory argument brought up enough. It matters and can be seen with steam peak.
Helldivers 2 succeeded on pc in markets where PlayStation isn’t dominant.