You're right. 1600*1200 was the max res supported by monitors back then. After 25 years my memory is rusty
still the point remains Voodoo 2 was already terrific by itself and in SLI it was just crazy.
Geforce 3 was never a Voodoo 5 5500 competitor, it was a gen ahead.
Voodoo 5 5500 was supposed to compete with the Geforce256 but they had to fix a few unexpected bugs that needed a new tapeout and they ended up competing with the Geforce 2.
Geforce 2 had just some very primitive form of non-programmable shaders and T&L was kinda useless if something like the PS2 could still throw more polygons on the screen.
It was with the Geforce 3 and the first programmable shaders that those features started to be useful but 3dfx unfortunately didn't make it that far.