N64 had a 4KB texture cache while the Ps1 had a 2KB cache. But the N64's mip-mapping requirement meant that it essentially had 2KB + lower resolution maps.
The streaming helped it a lot but I think the cost of larger carts was a big drag on what developers could do. It is one thing to stream textures but if you cannot afford the cart size in the first place it becomes merely academic.
The real problem was different. The PS1 cache was a real cache, managed transparently by the hardware. Textures could take the full 1 MB of VRAM (minus the framebuffer, of course).
In contrast, the N64 had a 4 kB texture RAM. That's it, all your textures for the current mesh had to fit in just 4 kB. If you wanted bigger textures, you had to come up with all sort of programming tricks.
The streaming helped it a lot but I think the cost of larger carts was a big drag on what developers could do. It is one thing to stream textures but if you cannot afford the cart size in the first place it becomes merely academic.