Liners are widely available, cost less to install and replace, and can be installed quickly. They are especially beneficial in cooler climates due to the lack of winter issues such as calcite crystals.
Even if the vinyl pool lining is damaged and faded in winter, its surface remains smooth so it won't wear down swimmers' feet. Another benefit is that the pattern and color don't drive the price of the lining.
Liners also do not chemically interact with water as quickly as cement-based finishes. As a result, the liner has less urgency for chemical equilibrium at start-up and less chance of pH spikes.