All we've seen though is a proliferation of tax deductions for varied interest groups. There's also something to be said for simplicity in the tax code itself.
Every government action can, with sufficient motivation, be understood as a handout to an interest group. For example, the biggest tax deduction, mortgage interest, can be analyzed as a handout to the interest group of "people who want to own houses." But I don't think that analysis is particularly meaningful and I would say that's not a correct understanding of the tax code. The vast majority of deductions exist specifically to incentivize behavior Congress thinks is important to society, like buying real estate, investing capital rather than leaving it lying around, giving to charity, etc., etc.
You might dispute the importance of incentivizing a particular behavior, or dispute that a particular incentive is working correctly, but it seems pretty facile to dismiss the whole policy set as handouts to interest groups and suggest that the government just shouldn't incentivize behavior with the tax code.
Frankly I think if the goal is to reduce complication as experienced by the citizen Warren has the right idea. Just have the IRS do your taxes for you unless you're super rich or complicated, and send them to you to sign off on.