American legislators seem to loooove "means testing" every government-provided service. Maybe it's a misguided version of that?
Free-file is useful when all you have is 1-2 above-board wage earning jobs, maybe with a 1099 contract job where the employer is nice nice enough to pre-fill the form out for you.
Once you start dealing with non-trivial amounts of dividends, interest, securities, partnerships, real-estate, you really do need a professional to keep things organized.
For some people. A person working a single job as a programmer earning $300k in straight W-2 income (no RSUs, etc.) does not have more complex taxes than a person earning $100k from a combination of their podcast + a few rental properties. There's no logic to means-testing this kind of service, where there would be for feature-testing (i.e. "Does all your income come from your job?").