Well, you've flagged the point. These people, about 10% of the population, that own small businesses are in the minority. They're likely to be an explicit disadvantage in this system. This is a segment that you probably want to use tax policy to protect, not harm.

Further.. it feels like the goalposts have moved on this since it last came up. I don't need the IRS to do my taxes for me, I just need to be able to login to the IRS, pick a form, fill it, and submit it.

E-filing should be free and available to everyone. If you have that, I'm not sure what the value of having it prefilled for me is. In particular, if you just have a single W2 to work from, there could be a 1040-SUPER-EZ where you just enter a serial number from your W2, have it fill from that, and then submit.

You can make this easy without putting everyone under the thumb of the IRS.

> what difference does it make to fix it vs making it all on their own?

That sounds like a big difference to me. The former would require government knowledge of every single transaction you make/receive, while the latter does not.