Why is there a debt ceiling?

A limit on the total debt the US Treasury can have when borrowing money to pay the bills the US Congress has authorized spending money on. The very definition explains that the Congress has already approved the expense. Need there be a redundancy to remind Congress that they are deficit spending and that the US debt has risen to higher levels than ever before? Do we really need another thing for Congress to politicize and drag through ridiculous partisan posturing? They OK'd the expense already. Why must they again decide to pay the bill they already agreed to pay? There is no Constitutional requirement. Wouldn't it be better, if one party or the other wanted to blow up the US economy by defaulting on our loans and debts, that they need to make the extra effort to do so rather than having to make the extra effort not to? It's almost like they made it up just to have another thing to faux argue about.

How about, from now on, just telling the US Treasury, if a legitimate bill comes due, pay it. If you need to borrow money in order to do so, do it. We the US Congress understand perfectly well that if we continue to spend more than we collect in revenue, this will be a regularly occurring process. Just let us know how much debt we are in each quarter so we can keep a running tabulation to blame each other for.