I have since gotten out of this business, but I used to prepare tax returns in a small town. People would come to us with 1 W-2, and a few dependents to claim. Take me all of 5 minutes to do the return, especially if they were a previous client as it would pre-fill prior information. We would collect anywhere from $150 to $200 for a return like this, because we would file it rapid refund so they could get a check back from the bank the next day. I told people they could E-file the whole thing for $75 and get the money in a couple weeks, sometimes less than that if you timed it right, but they wanted the money the next day. Sometimes people would even pay more and get $1000 instantly, and the rest the next day.
These same people wouldn't drive 2 blocks down the road to the public library and file for free and wait for their refund, so what makes you think they would file it for free with the IRS? Also a lot of these people were lower income people who didn't even have a bank account because they don't trust banks, what makes you think they are going to trust that the government is not screwing them on their tax return? I wouldn't trust the IRS. I personally saw many mistakes the IRS would make processing people's returns, which would cause them lots of time and money to get straightened out.
For the above reasons, this will never happen.