Yeah I understand they were all 6th gen. My point was just that it doesn't really make sense to blame the Dreamcast failure on its timing. Dates also matter:
Late 98 was release in Japan
Late 99 was release worldwide
Early 2000 was PS2 in Japan
Late 2000 was PS2 worldwide
Early 2001 Dreamcast was killed
Late 2001/Early 2002 Gamecube and Xbox
The meme makes it look like the Dreamcast popped up late, but timing was not the reason for it's demise at all. PlayStation dominating the market, as you mentioned, was probably the biggest one. People knew the PS2 was around the corner and the Dreamcast had barely been out in the EU by the time the PS2 was strutting it's stuff on the Japanese market.