This is one I'm happy to help with :D

It started way before GPUs were ever made. Reproductions of 'master works' were used by students of art.

Caballero Chubin (yes, that was her name) was one of the first to comodify this, way before the printing press. She would cut the master work into square sections, each to be reproduced independently by students, to then be stitched together and resold as a replication.

Notably, Chubin's Grid it was not a simple grid, but rather, semantic "sections". E.g. She would make sure there was no boundary over Mona Lisa's face, and have the same artist depict the whole section.

Chubin maintained an index of who worked on which section.

Cutting into sections enabled rapid production of a single reproduction, but also allowed reproductions of part of a whole work (say, of only Lubbert Das's gaunt visage) to be made and sold.

This same concept was applied to early computer graphics. Tiling is used by modern renderers, but the Chubris matrix (a portmanteau of Chubin and a developer known only as "Vris") intelligently used larger tiles for less-complicated and less-important scenes.

The "Chubris matrix" is not the grid itself, but rather, an optimal way to define and index sections of the grid. (This was when every byte mattered, remember).

The indexing was used as the inspiration for foveated rendering for VR, but also as the inspiration for PNG's compression algorithm, and more.

TLDR: It defines a non-uniform grid which is very useful for rendering.