That is what it would seem like but it's not true. Tax revenue isn't only collected once. When I spend money at a store, that's income to the store and that itself is taxed. That store spends the money to buy the goods they are selling, so that purchase is taxed. And on down the line.
This is the power of the free market. A very imperfect comparison would be to compound interest. There isn't just 1 transaction, you get more money in after each transaction on down the line. It's why food stamps actually return MORE money than is put in. For every dollar given out as food stamps, the tax revenue is over $1.50. linky
Now, food stamps for everybody doesn't scale to the entire population but for low income people who need it it's really no brainer economically.
The larger scale of this is economic stimulus. Putting government money into infrastructure. It is things that have to be done, and it keeps the wheels of the economy turning say, during a recession. By spending money to build a road, you pay the construction company. they pay their workers. The workers buy stuff. The stores buy more stuff to reflect the demand. That's how an economy works.
So by the gov putting money into an economy it keeps it moving when there is less private or consumer demand due to a recession.
The real kicker to stimulus is you also do it when the interest rates are low. And they are at historic lows right now. It's never been cheaper to deficit spend. Better if you don' t deficit spend, but that's not the world we have right now. We need to fix our infrastructure and grow the economy.