The IRS not having their own software for filing doesn't prevent most US taxpayers from e-filing for free using online software. The existing vendors offer free filing to those under 66k USD income, as they have for years (at varying dollar amounts).
The one that was painful to me was when my own state changed online filing systems and eliminated the system used for individuals in favor of "enhancing" the one for businesses. I was kind of hoping they would have remediated that by now, but no such luck. Now I have to *shudder* put a stamp on an envelope and walk all the way to my front door then lean out and raise the flag on my mailbox to avoid paying 20 dollars for e-filing.