The late 80s were defined by the "Desktop Publishing Revolution." While Adobe was busy creating the PostScript language that made printers understand geometry, they needed a tool to create that geometry.
In the early 1980s, the desktop publishing revolution was in full swing. Apple's Macintosh computer had just been introduced, and designers were eager to create digital artwork. However, the software available at the time was limited, and designers had to rely on primitive programs that couldn't quite deliver the level of precision and control they needed. adobe illustrator versions history