I never read the book when it came out in 2005. At the time, I was in my early 20s. I've always had interest in doing so but never got around to do it. It probably captures pickup well from the 2000-2004 era. I participated in that era.
In the first half of the 2000s, online dating websites weren't as big as they were from 2006-2012. Swipe apps changed it all around 2012-13.
After 2013, the number of practitioners of in-person approaching decreased. Swipe apps more affected bar approaching than non-bar approaching, since non-bar approaching has always been a bit of a niche activity. Few men have the guts to approach a woman in a non-bar setting while sober whether it is 1980, 2005, or 2021.
It is my understanding that The Game never really covered day game (non-bar approaching), which I liked it. I didn't really get into day game until the early 2010s. I did a little bit of day approaching while hiking in the mid-2000s but never did any grocery store, mall, gym, or fitness class approaching until the 2010s. One of my biggest game regrets is not doing day game on my college campus while in undergrad. In undergrad, more of my approaching was done at night at large residence parties (not really social circle game, closer to bar game) until I was 21 and then it was mostly bar game in my early 20s, which is right when "The Game" was hitting it big.