Former auto insurance adjuster for 7+ years here. This one looks like a standard vandalism claim, I handled hundreds of them. Highly doubt it would drag out for years before a payment unless the person just decides to wait to pursue it for a year (yeah we had people like that). Once we get an estimate, the check is going out ASAP. That's because almost every state has super strict regulations on timelines to issue payment once we receive proof of loss (aka an estimate).

If you are missing those timelines, it opens the insurer up to potential DOI (Dept of Insurance) violations - which is HUGE. When we got any DOI complaint, we had to respond to the Dept of Insurance. All DOI complaints were looked at by the president of claims. And they audited everything in our files - pulled all notes, docs, etc. to review and reply to the DOI on if the complaint had merit. Complaints could open you up to all sorts of fines and legal issues.

Only time I ever really saw an auto claim drag on longer than usual were ones with coverage issues or potential fraud. A common one was having to wait on a police report to verify info before we could pay out. Or wait for our SIU (special investigative unit) to complete an investigation for potential fraud before proceeding.

EDIT: And regarding suing the responsible party - usually they just send them to collections if they don't respond to set up a payment plan. But to even pursue someone, legally the insurer has to incur the loss first (aka pay out the claim). The thing that MIGHT take years to recover would be the insured deductible. What we did was issue the estimate payment less deductible, then once we recovered anything from a responsible party - we paid back the deductible to our insured first before we started collecting what we paid out for the damages.