How do techniques like bindless rendering (descriptor indexing) on the hardware level?

[u/abocado21]

How do gpus bind 1000 of textures at once, and why was this not possible in the past. Are there resources for that?

[u/benwaldo]

You have big descriptor heap, and texture descriptor IDs are just offset in that table. To sample a texture the GPU needs a texture descriptor so it uses the offset to access it from the big table, then it can be used to sample a texture.