In 1998, Intuit hired a former lobbyist named Bernie McKay to be their vice president of corporate affairs. The year they hired this self-described "Darth Vader", Congress passed a massive bill ensuring the IRS "should cooperate with and encourage the private sector" when it comes to electronic tax filing.
Four years later, the Bush Administration considered creating a (free) electronic filing system of their own to help simplify the process. This would be a direct competitor to companies like TurboTax, however, so before any progress could be made, TurboTax lobbied a bunch of Republicans into contacting the IRS. They even lobbied the White House directly.
The IRS was suddenly accused of making "secret plans to undercut the industry", but thankfully Intuit stepped in to help. Intuit would create a free version of their program for lower-income users, to ensure more people could easily file their taxes. The IRS was forced to acquiesce as they were sure they'd never get the funding to set up a system of their own after Congressional opinion turned against them.
As recently as 2018, TurboTax was inches away from forcing through a law that would essentially make it illegal for the IRS to ever create their own filing system. It only fell through because journalism outfits like ProPublica dug into TurboTax's decades of shittiness in response to the bill. Here's a graph that shows just a few instances where TurboTax stepped in to screw meaningful reform from happening.