That actually makes sense. I don't know why you didn't expect it. The PS2 did have first party games, but not close to the extent of what was on GC. Keep in mind, this was still when Sony didn't have a consistent mascot and they were just throwing whatever worked. They literally did not get official permanent face until Astro Bot.
I'm gonna ackchually here, but the PS2 had 127 first party games, as opposed to the Gamecube's 45. A lot of those were sports games and stuff like Singstar tho. Anyway, just seemed odd considering the PS2s massive install base and high attach rate, and the sheer number of first part games. Then again, PS2 had huge third party support, could be first party did less because third party offerings were so strong.
The current-gen XBoxes don't seem to be on here at all. Did they actually not have any? I mean, I'd heard the joke of "Microsoft released more first-party studios than first-party games", but....
Yeah, that doesn't feel right. There's been two CODs under Microsoft, and two Forzas, a Halo, Starfield and Indiana Jones. Those most definitely all sold more than 1 mil copies. Unless of course they only counting physical sales, not digital, and Xbox Series has been overwhelmingly digital since pretty much day one.