48 yr old post laminotomy for severe spinal stenosis, 5 orthopedic surgeon indicate double fusion, but will never do it, l3, l4, l5 degenerated?

Difficult to answer: Sometimes fusion is the right answer but only if all other conservative treatments have failed. There are other less invasive treatments that might help but check with pain specialists for another opinion. Degenerative disks are not necessarily a contraindication for fusion, if warranted by your situation. I do agree though that back surgery should only be done if there is a good reason to do so.

Depends: All spines degenerate but not all spines then need a fusion. There would have to be another reason like an instability that can develop after prior spine surgery. Sometimes ongoing degeneration after a prior laminectomy leads to restenosis due to further facet & disc degeneration & a repeat decompression where there is a chance of destabilizing the spine by further bone removal requires a fusion.