It killed any and all momentum Id and doom 3 had
I disagree on this. Half life 2 sold it's self on physics and Doom 3 sold it's self on it's lighting system and graphics. HL2 wasn't a slouch in either but Doom 3 looked stunning back then and would constantly get multi page coverage and covers. HL2's hype was bigger but Doom 3 wasn't competing with it the same way modern games often compete. I wanted Doom 3 and I wanted Half-life 2 and I was going to enjoy both of them on their own terms. FPS fans were used to juggling multiple games so it wasn't an either/or when Doom 3 released 4 months earlier and had it's little duct tape mod controversy dominating it's discussion at release.
From Wikipedia.
In the United States,
Half-Life 2's PC version sold 680,000 copies and had earned $34.3 million by August 2006. It was the country's 17th best-selling PC game between January 2000 and August 2006.
[51] It received a "Platinum" sales award from the
Entertainment and Leisure Software Publishers Association (ELSPA),
[52] indicating sales of at least 300,000 copies in the United Kingdom.
[53] Forbes reported on February 9, 2011, that the game had sold 12 million copies worldwide.
Doom 3 was a commercial success for
id Software. id expected to sell 4 million copies of the game.
[81] In the United States, the computer version sold 760,000 copies and earned $32.4 million (~$45.5 million in 2022) by August 2006. It was the country's 16th best-selling computer game between January 2000 and August 2006.
[82] Its computer version also received a "Gold" sales award from the
Entertainment and Leisure Software Publishers Association (ELSPA),
[83] indicating sales of at least 200,000 copies in the United Kingdom.
[84] By the beginning of 2007, over 3.5 million copies of
Doom 3 had been sold worldwide (compared to 2-3 million copies sold for the original
Doom and 2 million for
Doom II),
[85][86][87] making it the most successful project by id Software at the time.
[88][89][90]