I only insure expenses that not capped, generally evac and medical.
The cost of the trip is capped, and I've already spent the money, so I don't have any financial risk or exposure. The worst that can happen if I have to cancel my trip, is that I don't go on vacation. There are no financial risks. A result that is sad, but not bad.
Medical expenses or medical evacuation however are essentially unlimited and pose significant financial risk, albeit with a very low probability. These I insure with third-party medical insurance being the primary insurer and my regular medical insurance being a secondary payer.
I buy medical evacuation insurance for which I make the decision in which hospital I want to be treated. Most people return to their home hospital.
All other vacation expenses are not material to my long-term financial health.