Maybe it's a self-fulfilling prophecy kind of thing, do we have high speed games today as we used to, e.g. [1]? If game developers assume shitty hardware and software, they won't make things that require better latency.
Secondly, not every PC in 1999 was capable of even running QIII (let alone at a high frame rate).
During the days of true low-latency gaming, actual game frame rates were in the low 20s and even consoles rarely achieved 50 or 60 fps.
If a game was playable at 20s of fps, I don't think it deserves a title of low-latency gaming.