Not..entirely true.
My 2016 taxes were professionally done, but we somehow forgot to include one of the something-something-1099 forms from a brokerage firm. The brokerage reported some RSU stock-sells to the IRS but didn't report the cost-basis, and so the IRS assumed the cost-basis was $0 and thus taxed the full sale as income (effectively double-taxing all the RSUs). They just sent a tax bill for something like $20k plus a bunch of fees and interest.
It's an accounting-error so we won't owe much, but I doubt we would have seen this mistake if the IRS had just told us a total amount to pay. We have two tech-job incomes both of which are highly-dependent on equity, so we'd almost certainly end up getting a CPA to run all the numbers again anyway.
I'm a fan of reducing bureaucracy of double-reporting tax info, but I'm personally unwilling to trust that the IRS and various banks / brokerage systems are up to the task of generating trustworthy data (and/or erring on the side of the taxpayer in situations like this).