The framing you are missing is that it is not for your clients. You are comparing the product against your service, for the people who already buy your service, and on that comparison it will always lose and you will always stall.
The product is for the people who were never going to hire you. That group is much larger and their alternative is not your excellent service: it is a spreadsheet, an afternoon of guessing, or nothing at all. Against nothing at all, sixty percent done automatically is transformative.
Once you see it that way the landing page writes itself, because you can be completely honest:
- Who it is for: people who cannot justify a consultant
- What it does: the mechanical part, reliably, in minutes
- What it does not do: the judgement, and you say so plainly
Saying what it does not do is not a weakness in the copy. It is the thing that makes the rest believable, and it filters out the people who would have been disappointed - who are precisely the people who should be hiring you instead.
This also solves a problem you have not hit yet: if you sell the product to your service clients as an equivalent, you cannibalise your own good business and disappoint them at the same time. Two products, two audiences, two prices, and the honest gap between them stated out loud.