FranklyWhy it is free
The inspection costs the company an hour because it expects to sell the repair or replacement it finds. Nobody is hiding this; it is a normal lead-generation model. The consequence is simply that the person assessing your roof is paid when work is sold.
What it is genuinely good for
You get eyes on a roof you cannot safely inspect yourself, photographs of the actual condition, and a written estimate. All three are useful inputs. Take the photos and the written scope; treat the urgency that comes with them as a separate thing.
The pattern to watch for
Findings that arrive with a same-day discount, a full replacement recommended without the reasoning shown, or photos that could be any roof. Ask for images that include a recognisable feature of your house, and ask what a repair-only option would cost.
Use it as step one, not the decision
The sequence that works well: take the free inspection, collect the written estimate, then have it reviewed by someone with no roofing work to sell. You keep the free information and remove the incentive problem.