the Xbox was a financial disaster that was basically a massive loss leader by a larger company that could absorb it just to tee themselves up for next generation. Microsoft’s Xbox division was $2bill in the red when it was all said and done.
the GameCube sold the worst of all the big 3 consoles (Sony/Microsoft/Nintendo) at 21 mill total. Xbox 24mill. The Dreamcast sold just 9mill. That’s less than half of the 3rd worst selling system.

You’re cherry picking your numbers it seems to ignore Dreamcast’s count at 9mill units sold. First years are only part of the story. The story is they did very poorly.

Your comparisons are not propping up the Dreamcast. The fact that it did worse than GameCube and Xbox despite the fact that both did not do well at all just further indicates how disastrous it was.