Their ability to position correctly allows them to place parts in the right place at the right time with less margin of error, which is vital for large-scale mass production enterprises. Cartesian robots, or Linear robots, are easier to program than other moving robots.
The reason for this is that they move on a simple X, Y, Z axis. Another advantage is that they are less affected by space constraints on the floor. This is because they are easier to assemble than other robots.