There's no "entitlements" you can cut that wouldn't cause more harm to the economy than they would save up in federal spending. And there isn't enough income that taxing it to pay off the debt would be practical. You have to tax capital, that's where the entire world's wealth has been sucked up in the last decades. That's the only solution that doesn't involve the country defaulting on its debts.

Billionaires know that and are already starting to speak against such taxes[0], before there's even any real possibility of them being adopted. They would rather see everything turn to shit than give back a single cent.

[0] https://paulgraham.com/winc.html