Like anything, it depends on your level of comfort with risk. I do not buy trip insurance or extended warranties on tech purchases. I can afford to "take the hit" on the rare occasions where those types of insurance would be of value.
I do however have life, car, extended health, income loss and household insurance, because they cover some fairly catastrophic potential losses.
I travel to Disney a lot by most non-Florida resident standards, six trips last year and well over 50 trips since 2001. Trip insurance never would have been claimed against for any of those trips. Had I purchased it for every single trip, I would have invested thousands of dollars. I have the wherewithal to cover any unexpected expense that could arise on any given trip and the cost would not exceed what I've already saved by not purchasing insurance. However, if the sudden cancellation of a trip where you would lose deposits, have to pay for replacement clothing/luggage/toiletries or have to pay for emergency health care that isn't already covered would be a financial hardship, then buying insurance is worthwhile.
I do buy insurance when taking cruises [my son and I are booked on the WDWMagic Family Cruise in June
] because my out-of-country health coverage does not have sufficient coverage to take care of an emergency evacuation from the ship and that's an expense I wouldn't readily be able to absorb.
It's also worth checking what you may already be covered for by your credit card(s). I have cards that automatically include fairly comprehensive trip cancellation insurance if I purchase the trip with their card. Some are better than others and some have very extensive exclusions and conditions.
