The most important thing to understand about the rise and fall of 3dfx is that one, it was an extremely short period of time (around 2 years), and two, it occurred during a time of incredible and rapid change in the PC industry overall.
Every other day something new and amazing would emerge - be it some revolutionary tech, a genre-redefining game, some new buzz sensation on the internet. 3dfx was one story among thousands of similar stories that were saturating the mindset of young gamers at the time.
So what was it like watching it die? Well we could barely notice, not because we didn't care, but we were too busy playing half-life until 5am in the morning. Do you get it? As amazing as 3dfx was, it was just one amazing thing out of a world of amazing things we were being hit by almost every day.
When it finally did die, we could barely even remember those days just a few years earlier. Why? Because that's what happens when you experience rapid change. You are still adjusting to the new awesome world you have woken up to, and you have still yet to fully comprehend the change that has taken place, or properly realized that 1997-1998 might just have been the two greatest years in your life, with 3dfx at the heart of them.
It has basically taken 20 years of watching the PC industry rise and then stagnate to the point of boredom...most of us now have steam libraries of thousands of unplayed games from previous gaming eras...still working through playlists of games 10 years old....to suddenly look back on that time and remember the first time you fired up GLquake and saw the future for the first time, and realize, yeah something incredible happened then. And for me it wasn't even on a 3dfx card (yet), it was a Riva 128.
The point is we care about the rise and death of 3dfx now more in retrospect than we did at the time. The question for me is...why 3dfx? Lots of other companies rose and fell, why don't we talk about them as much and wonder what if they had survived? I personally have a greater affinity for Sierra and often wonder what would have happened if it didn't sell out (and then go bankrupt due to fraud), and imagine if we had seen more sequels to all those amazing adventure games from the era. And to be fair there is a lot more being done about the history of Sierra than 3dfx...multiple books written, and a new movie is currently being produced (https://www.youtube.com/watch?v=0WqaPCJRwko).
But if you really want to get a feeling of the spirit of the time of 3dfx, I would look no further than this mind-bogglingly good youtube channel (https://www.youtube.com/@quakespeedrunsexplained). The fact this channel exists to me means that time is still alive and captured so perfectly in these videos. Also too see an even earlier time is still alive and well, check out this (https://www.youtube.com/@doomwads).