For most people, you won't have these issues. For those that do, what difference does it make to fix it vs making it all on their own?

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.

> They're likely to be an explicit disadvantage in this system

How are they at a disadvantage? Before, they had to do all their filing themselves, after, they have to also do all the filing themselves.

Why would they be at a disadvantage? As a small business don't you keep your business accounts separate to your personal accounts, and have an accountant to at least audit them each year before submission?

I think you are both right. There can be a process for business and personal. The two are different, why lump them together?

> 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.

It isn't. Most people only pay tax on their income, which is already sent to the IRS. Just pre-file it and ask the payee to approve it. If you have more complicated taxes, you can just decline the pre-filed and file your own, like you already do.