16 bit on TNT was fine for most of what I played at the time, although at the time it was mostly Quake/Quake2 and a few other games. Admittedly I was much more into 2d (especially strategy) games at the time, so 2d perf (and good VESA compat for dos trash and emulators) was more important to me for the most part.
I think 3dfx had a good product but lost the plot somewhere in between/combination of their cutting 3rd parties out of the market, and not deeply integrating as quickly vs considering binning. VSA-100 was a good idea in theory but the idea they could make a working board with 4 chips in sync at an affordable cost was too bold, and probably a sign they needed to do some soul seeking before going down that path.
Now, it's possible that comment is only discernable in hindsight only. After all, these folks had seemed like engineering geniuses with what they had already pulled off. OTOH, when we consider the cost jump of a '1 to 2 to 4 CPU' system back then... maybe everyone was a bit too optimistic.