There is waste. A God awful amount of waste, fraud, and abuse. You don't rack up a 1.8 trillion deficit and a debt per capita that is 7x the income per capita without waste, fraud, and abuse.
The problem is that while common sense would dictate those nonsensical expenses as such, they were part of the official process, so it was all legalized, so they avoid the FWA labels because the rule writers have made it so.
The problem with your argument is that Social Security (old people income), Medicare (old people healthcare) and interest on the national debt account for fully one half of total federal spending. Add in national defense and you reach two thirds.
Interest is trivially accounted for. We know how much debt is outstanding.
Social Security and Medicare expenditures are well within 5% of what should be expected, given the total population of the US and its age distribution.
Your God Awful amount of waste, fraud and abuse reduces to a fraction of a fraction of the total budget. A tiny fraction of a big number may be a big number, but it simply doesn't matter structurally.
The only way out is to cancel the entire military, slash social security or raise taxes. The rest of the stuff (even if it is purely waste with no useful purpose) simply doesn't add up to enough dollars to fix the budget.
I know this isn't what anyone wants to hear, but numbers are numbers and you can't just wish away unpleasant realities.
A solid portion of the 1.8 trillion figure the GP quoted was also the insane spending that had to happen to keep the economy somewhat afloat during the pandemic.
Of course in proper propagandist fashion, we only ever hear about how much money the undeserving poors got, and nothing about the millions upon millions of dollars in loans given to private businesses and their owners that were definitely, 100% used for them to weather the pandemic, and later forgiven despite being explicitly loans.
There is of course waste. But the budget for everything apart from social security, medicare/caid, and defense is very small in comparison to those. The US could cut everything except for those three and it wouldn't delay the debt bomb's detonation by more than a year. Current projections are around 20 years of current trends. The US has to keep borrowing, or the world economy breaks down with no reserve currency. The trick is that the borrowing needs to keep increasing the gdp at the same rate as the debt. I.E. the loans have to be spent on assets. That is not currently the case.
The problem is that while common sense would dictate those nonsensical expenses as such, they were part of the official process, so it was all legalized, so they avoid the FWA labels because the rule writers have made it so.