This is one of the places where lining genuinely earns its keep, because of everything sitting on top of the pipe.
What you would otherwise dig through
Old sewer lines here run under established gardens, brick and shell driveways, courtyards and mature trees that took decades to grow. Open trenching means destroying a good deal of it and, on a property subject to design review, potentially triggering approvals you would rather avoid. Lining works entirely through existing access points.
It fixes the cause, not the symptom
Roots get in at the joints, and brackish groundwater and sand get in the same way. A liner has no joints, so it deals with both at once rather than buying you a season.
Newer homes on the island
Where a house has been rebuilt in recent decades, the sewer line is much newer and lining is unlikely to be what you need. Ask to see the camera footage — a blockage there is far more likely sand or something that went down a drain.
When it cannot be done
A collapsed line, or one that has lost its fall and holds water along its length, cannot be lined. Better you hear that after we look than partway through.