Lack of Profit...
Outriders developer People Can Fly have not received any royalties from the said title nor do they know the amount of copies sold. The developer believes publisher Square Enix’s decision making led to the game’s lack of profit.
They explain on their investor’s website (note: site link is in Polish), People Can Fly were meant to gain royalties for the first quarter on sale by August 16, 2021, but did not.
Various reasons by People Can Fly were outlined, namely, Square Enix overspending on the game and releasing the game Xbox Game Pass (meaning no sales/money is made).
The game is still being worked on, though People Can Fly reason its best for releases to develop IP for themselves rather than being under the hands of publishers.