Glide was a roaring success that helped 3dfx to dominate the industry for a number of years. It would still probably be around if 3dfx hadn't gone totally nuts.
Vendor lock-ins and proprietary tech only fails when they don't have a compelling advantage - that's why PhysX was a failure, it just didn't matter enough to make the AMD buyers switch to Nvidia. I strongly suspect that this won't be the case in the opposite direction, with Nvidia buyers really wishing they had an AMD card instead because of Mantle.
That's how it was for 3dfx, so why wouldn't it be the same for AMD?
Really. Since you weren't around back then and make that completely obvious, let me clue you in. Glide was created back when
D3D didn't exist with the Voodoo I. There was NO standard, there were 11 standards all competing with each other - every chip had their own 3d API. PowerVR had their own thing going on. So did the rendition verite. In fact, when D3D became ubiquitous there was no longer a need to get a 3dfx card. Eventually 3DFX fell so behind on the D3D performance curve, this with other factors (V3 was a disappointment and late, purchase of STB, etc) led to their demise.
Thank you, drive through. Oh yeah. Speaking of which. Most glide titles did not have a big performance advantage over D3D. It was generally 10 frames if that - which didn't matter when 3dfx fell behind the curve in terms of D3D performance. The voodoo 3 was a disappointment but they barely managed to hang on. Let's see, from what I remember, the Riva 128 was the competing product to the voodoo2. The V2 was still better in terms of D3D performance, and very few titles used glide by that time. Then the Riva TNT was released - it was just better than the V3 by a mile. The V3 was also late and disappointing, with poor D3D performance. Shortly after, 3dfx went caput.
3DFX initial success had nothing to do with glide. They were successful because...well...mostly they were one of the first and they had the highest performing overall part by a mile. Nobody could touch 3dfx performance by any metric. 3dfx was loved initially because they got in on the market early and they had the most compelling performance and hardware. Once that advantage went away, people stopped caring. It had absolutely nothing to do with glide, like I said glide was created because there was no standard in the early days. It was proprietary or nothing.