maybe because it had amazing looking exclusives like Shadow of the Collossus, Silent Hill 3 and Metal Gear Solid 3?
Metal Gear Solid 3 sold less than Melee or Sunshine.
Silent hill and Collossus was a niche games...
That's not the reason, what is the best seller on PS2? Grand Theft Auto...
The TRULY reason is just the marketing, the sales of the PS2 games confirmed this.
2020 predictions: NSW 25m, PS5 6m, XSX 4.5m, PS4 9m, XB1 3m
In December 2019 i predicted 21m Switch, but that was before COVID, obvius increased my predictions.