I disagree often on this subject. It REALLY matters who you get your policy through and what the exclusions are. I have had three policies over the years as I fix things with a screwdriver, duct tape and check book. I am obviously not mechanically inclined nor do I have any expertise. I know enough to avoid being scammed but not to fix.
In those three service policies I have been under what I paid once and over in paid repairs twice. Labor IS included in mine. I pay the deductible and they pay the remainder of the repair. The last policy paid out over $5k the cost. I like to sleep at night and not worry what a major repair may cost me.
You must read the policy, know what you are getting and be sure to get any repairs PREapproved. Maintenance must be kept up and sometimes an inspection of the RV must occur before they will issue a policy.
For me it works. I know that any service/insurance policy is betting I will not get more than I paid. Many do start their own repair account and bank the similar money. Really is a matter of personal expertise and level of comfort with paying for a large repair.
Read the fine print before purchasing and compare to other potential policies. They vary wildly in cost and coverage. Happy Trails!