People had to put up with deflationary shocks and yet robber barons built their empires all the same. Hard money doesn't stop r>g, it doesn't stop expected returns from growing increasingly burdensome, and it doesn't stop assets from appreciating relative to wages. It doesn't actually deliver the things we care about.
It delivers plenty of things we don't care for, though. History provides the most lurid examples, but we have modern ones too. In the US, Clinton balanced the budget and the macroeconomic consequences broke something very important (audience participation: what was it? Hint: we call them "dual deficits" for a reason). We quickly took our finger off the stove, though, so it was only a lesson for the observant. Germany on the other hand kept its debt brake in place, which mechanically suppressed investment (macro 101 quiz time again: why?) with staggering consequences, leading to one of the most underinvested economies in Europe and almost completely shutting them out of the digital revolution, in which I privately suspect they'd have otherwise participated fabulously. In any case, had Clinton installed a debt brake, that would have been us. HackerNews, YCombinator, and all the ZIRP babies around these parts would have been among the most affected. The Magnificent 7 would not have all been in the US.
So no, deficits aren't the root of all evil and the appropriate deficit is considerably north of 0. That said, it's south of where we have it. Interest rates are the gauge. Is money being pushed in (low rates) or pulled in (high rates)? We are transitioning from the former regime to the latter regime, partly due to imperial retreat, partly due to crisis-level spending in a time of no crisis which is wildly irresponsible. The US is clearly headed for a debt crisis. But the answer is belt-tightening and either gentle-repression-over-time like we did after WWII (fat chance) or an inflation spike followed by a rate hike (probably several) until the bond market is happy again. It's going to be bumpy, but not as bumpy as the hard money counterfactual.