Just to add: 30 years ago there was nearly as much hand-wringing about pork-barrel politics as there is today about our insane partisanship. It led to its fair share of sub optimal decisions...
That's because we passed the "We have to pay this off" point, passed the "Our children have to pay this off" point, passed the "It's okay if we never pay off the national debt as long as our GDP grows faster than it", and are now at "Now is not the time to worry about the debt, people are revolting on the streets!"
We know how this rodeo ends, but nobody wants to think about bad things.
You've still got less debt vs gdp right now than you had at the end of WW2, so this is definitely not the real/actual reason.
Looking at the UK's debt over 3 centuries, we've often gone way above 200% debt, and you're only at like 120% at the moment, so it's not even a lot, historically speaking.