When you have done it for 30 years, all u need is a visual, I've won every bid so far this year just due to the technology of the drone. Customers love the hands on bids
I know of someone nearby me who took his roof inspection exam (and is 107). He keeps pretty busy doing inspections for insurance companies, roofing companies, home inspectors (since few are 107 certified and the authorities are VERY active here) and homeowners. No one wants to climb ladders and walking around a roof can cause damage in and of itself.