You would be frightened if they prepared your taxes for any more than the simple return, ie some W2s. I would not even want the IRS to automatically prepare taxes for "simple" forms such as 1099-Int/1099-Div or 1099-B for stock sales.
And I do not say that from a "job security" perspective for the tax work we do.
The solution isn't government prepared taxes, it is less taxes.