Sure, but then why not just roll it into the IRS’ own web portal instead of letting every service roll their own and potentially screw with it (like Intuit did when it prevented Google from indexing its Free File tier)? The result is far more consumer friendly and potentially allows for greater integration with and prepopulation from other government services.

So then the right question to ask is "why is the tax code so complicated?"

Yes, EZ file should work for 99.9% of the US. But it doesn't, because the tax code is horrendously complex