> Why bother investing in more, if none of the arrests result in charges?

UP is not complaining that none of the arrests result in charges. (They are complaining that the DA is settling for plea deals to lesser charges than they would prefer and not trying to employ cash bail as pre-conviction punishment for disabling [by incarceration of those who can’t afford it] suspects and deterring potential future criminals instead of not using it when it is not necessary to secure appearance of a suspect legally presumed innocent.)

Also, it's well known that sufficiently visible security is a deterrent to crime, which is better than after-the-fact arrests, so an eruption in undeterred crime is evidence of a need for more and more visible security.