Hitting the US debt limit does NOT mean we have to default on our debt. There are a myriad of other options, namely: reduce spending, reduce headcount, maybe even close pointless departments, or delay new projects. Even with our large deficit there are more than enough tax receipts to cover debt repayment and entitlement spending. Which are the only things the US is absolutely required to spend. Everything else is some degree of optional(I am oversimplifying for brevity).

Any sane entity would reduce spending if their revenue came in lower than expected. If I lost my job I’d immediately cut spending on anything optional, but would still pay my mortgage if I was able. Same general principle.