> If reddit or nytimes has a bloated, intermittently failing SPA site, that's an annoyance. When it's a form to apply for unemployment, ACA health care, DMV, or other critical services, it's a critical failure.

Unfortunately the incentives are backwards. Typically governments have to choose the lowest bid. Those private companies you mentioned can make more complex tradeoffs.

Sometimes, of course (cough Florida unemployment and covid tracking sites), failure in performance is by design.