I used to use TurboTax Free Edition, constantly frustrated with all the dark patterns used to try to trick you into switching to non-free. Eventually I started making too much to use Free Edition, which is right around the time Credit Karma started offering free tax filing, but I hated CK's UI/UX. It made it easy to miss a deduction, and it did once. I used TT to basically "prepare" my taxes, but not actually file so…
This seems much like an "illusion of choice" situation. Credit Karma and Turbo Tax are both owned by Intuit. (Not that you were fooled by the illusion, just that it stuck out to me.)