I figure that the percent of government income compared to GDP in the United States is too high.
And Warren's field of expertise is business, not government.
Government cannot, and should not, be run like a business. The inherent goal of most business to is grow and make money. If the government had the same goal (which in my opinion it currently does) it would eventually grow to the point where it consumed nearly all income. When was the last time you heard any government or publicly funded entity like a university say "we have more money than we need., give us less next year"? Very rarely.
Every year, they "need" more more than they did the last because they are motivated by expansion.
Warren may be qualified to talk about expansion as it relates to generating income, but again, that presupposes that our government should be expanding and not contracting - which is the political debate I am referring to.