For a normal person, if you spend $10k every month and have $8k in income, you will go broke eventually. Government does not have to follow the same rules as normal people.

The key insight is that government debt is in its own money. It can never go broke, because it can keep printing new money (more precisely new debt) to keep refinancing its debt.

This idea is sometimes referred to as "modern monetary theory". That's the idea that the national debt is just a number on a piece of paper. The national debt does not represent an obligation that someday must be repaid, because it can always be refinanced by creating new bonds. Debt for the Federal government is not the same as debt by a normal person.

The only limit is a hyperinflationary collapse of the monetary system.

This is really only true for countries like the USA, who get the perk of debt being in their own money. The Euro countries gave up this ability by joining the Euro. Most 3rd world countries will have their debt be in foreign currency, like US dollars.

Technically, the US does not print new money for deficit spending. Instead, the government creates new Treasury bonds, which are sold to the financial industry. The financial industry then sells bonds to the Federal Reserve, which creates new money to buy the bonds. The financial industry scalps a profit doing this.

You might ask "Why doesn't the US just print and spend its own money, instead of borrowing it from a central bank?" The answer is the lobbyists from big banks set up the monetary system like this on purpose, because it lets them scalp a profit on all government Treasury bond sales. As will all corrupt this, reforming this is impossible as the banks' access to free money also gives them an unlimited lobbying budget.

The US has a debt-based monetary system. New money is only created when someone borrows it. This means the national debt plays a key anchor in the monetary system. The government can always prevent a deflationary spiral by deficit spending. The reason deficit spending is a risk is that, during a severe recession, no new money is borrowed but all existing debts are still due. Money is created when borrowed, and destroyed when the loan is repaid. Thus there is a risk of hyperdeflation, which the government prevents by deficit spending.

Debt-based money is an inherently corrupt system, but reforming it is impossible. Too many people are making a fortune off the way things are now.

Notice that you have many debates covered in public about one aspect of corruption or another. You'll almost never hear someone publicly criticize our monetary system. Most people are unaware, and they're kept that way on purpose.