Why not use all those forms and prefill my tax form for me ?

If I disagree, I can add/remove/update it. If I agree, I just file

Asking me to collect those documents and reports the different numbers into a form, is not efficient, error prone and time/money consuming.

> Asking me to collect those documents and reports the different numbers into a form, is not efficient, error prone and time/money consuming

Exactly. That’s why they want you to do it and not them.

The IRS does it anyways to validate your return ...

It's marginally more work for them to tell you the results of their math. And compared to how many people file taxes it's a net benefit for society. Collectively paying a small group of people to do something for the benefit of many is like the whole point of government.

I don’t know that they do. I think they do sampling of higher value accounts and get out the full details for an audit.

I don’t know that for sure that.