Root removal is a two-part job done properly. First the mass is cut and flushed out so the pipe runs clear and the camera can see the pipe wall. Then the entry point is identified and sealed, normally with a patch liner over the affected joint.
Contractors who only cut are effectively selling you an annual subscription — the roots come back because the moisture plume from the leaking joint is still there attracting them. Sealing the joint removes the reason the roots grew towards the pipe in the first place.
Removing the tree is almost never necessary. Sealing the pipe is cheaper, faster and does not cost you a mature tree.