OG Xbox was somehow a success, at least for MS, it secured the 360, and that´s because:
- It took worldwide console sales second place from Nintendo.
- Brought franchises like Halo, Forza Motorsports, 3D Ninja Gaiden, Fable, which are relevant still today.
- Had less exclusives than PS2, but some of them were high ranked games and/or cult classics like Project Gotham, the DOAs, Otogi, JSRF, Panzer Dragoon Orta, US Shenmue 2, Unreal Championship, etc...
- Due it´s power, had the best multiplattform version of hot games like San Andreas, Splinter Cell, NFSU, etc.
- Had console-exclusive PC ports of historical games like Morrowind, Doom 3, Half Life 2, Far Cry, impossible to replicate on any other console from that gen.
- In regions like Latin América, or at least my country, Colombia, due the possibility of modding it and install on it pirated games and emulators, and also having Halo and hot 3rd partys, like Def Jam, GTA, NFSU, PES, Black, Burnout, Silent Hill, etc, it became the actual "On Vogue" console during mid 00s, even above PS2. Since PS2 price was too high during it´s first and FAT model years here, and DC and GCN were not that popular (but also not that unknown), lotta people here made the jump from PS1 straight to OG Xbox by 04 to 06, believe it or not. Of course PS2 was also way popular here (and PSP Too), but that happened when it became affordable with the slim model and specially after OG Xbox lost it´s impulse due to the first 360 years. So PS2 had it´s peak here on the second half of the 2000s and ultimately became the cheapest way to have a console with games still releasing if you couldnt afford Wii/360/PS3
So, call me crazy, but Xbox Series and even One would whish some of all OG Xbox milestones.