Adobe still actively trolls for unlicensed commercial use. If you use a cracked version of 19.0.0 to design a logo for a client, and that client is audited, you face fines starting at $5,000.
It was stable, fast (unlike some modern bloated versions), and became a gold standard for vector artists. Adobe Illustrator CC 2015 19.0.0 -64-Bit- Crack
You don't need the crack.