I'd have thought the government would need to maintain some expertise in the "industry" of collecting taxes, at least. When I file a tax return in Australia, I do it via a government website.
Also, the government provides free java/excel based tax filing systems with a certain level of sanity checking.
Apart from this there are several fremium sites like cleartax to help file taxes but they don't get to lobby.
(yes, corruption is inherent and tax evasion is rampant, but at least filing taxes aren't as painful as US tax filing seems to be)
It's only an argument that the state and local governments would need their own, parallel systems if they wanted to participate.
https://www.irs.gov/filing/free-file-do-your-federal-taxes-f...