Liner life depends almost entirely on installation quality. The host pipe must be jetted and descaled first so the resin bonds cleanly, the liner must be sized correctly for the pipe diameter, and curing must be given the full manufacturer's time at the right temperature.
Because the liner has no joints along its length, the two failure modes of old clay pipework — root ingress at joints and infiltration through cracks — are eliminated. In practice a lined run typically outlasts the original pipe by decades.
Ask for the post-installation CCTV recording. A good liner looks like a continuous glossy pipe with no wrinkles, no folds and no annular gap at the ends.