Hail storm totaled my roof and Allstate is low-balling hard

We had a pretty nasty hail storm back in February. Quarter-size hail, the whole neighborhood got hit. I filed a claim with Allstate right away, adjuster came out and spent maybe 20 minutes up there. Their offer came back at $4,100 for what my roofing contractor says is a full tear-off and replace job costing around $19,500.

I pushed back and asked them to explain the difference. They said the roof had "pre-existing wear" and they were only covering part of it. Mind you, the roof was put on in 2018 and this is the first time I've had any issues.

Has anyone dealt with Allstate specifically on roof hail damage? I'm thinking about hiring a public adjuster. Also wondering if I should get an independent inspector before I do anything else.