That implies the government would know significantly more about my life and my day to day affairs. That sounds like it would be a privacy nightmare.
That would be simple enough for most people (1 job, 1 home, maybe some kids) and it doesn’t require the government to know anything additional.
In that most common scenario no tax accounting service should be needed. Honestly a 1040 isn’t that complicated in that scenario either, but is still too difficult for a good number of people and it’s just unnecessary.
And if all you have is a W-2 you don't experience most of the complexity of filing as it stands now anyway.
They're suggesting letting the irs actually use the resources they already have to automate the vast majority of the people's taxes to save everyone time and money.
It doesn't have to be perfect to be a huge improvement.
(Also it’s rather ironic that people who think like you have been voting for the party which is currently enabling Palantir to build Chinese-style surveillance in America. But as long as the data is owned by billionaires and they promise to only use it against the “others”, I guess it’s fine.)