This is a very, very good and important point.
Gov't funded entities have limited resources (which are declining by the day -- DOGE, EVERYWHERE!). Everyone wants the thing/project that touches on them done perfectly. The street in front of MY house should be perfectly smooth! Cool, the city has 1200 miles of streets to repair and maintain, and a budget to maintain.....50 linear miles a year. So, each 50 miles can get touched - on average - once every 24 years. Sure, some higher-traffic stretches will get more frequent work....meaning that lower traffic streets like residential streets get stretched out to a 30 year schedule.
DA's budgets are similar. We want them to take care of ALL cases, and get those thugs off our streets. But then we demand that they blow 70% of their budget on two "high profile" cases, leaving few resources to deal with the other 5,000 cases on the docket.
Decisions have to be made, resource allocation has to be considered. Every public official I've ever talked to has said some version of "if you give me the money/budget, I will do exactly what you want - nothing would make me happier than repaving every street in town" (or words to that effect).