It’s repairable, but not a good project for someone without a lot of experience. It’s a big job, with lots of details that could go wrong if you’ve never worked with resins, glass, and core.
It’s very doable for someone with experience in those kinds of repairs. I have done repairs repairing cracked, broken laminate and replacing core so I have some idea of what’s involved. I’m not a pro but I have 25 years experience doing fiberglass work.
I’m not familiar with the construction of that particular boat’s cockpit, but virtually all boats have core on the cockpit floor. That core is almost certainly rotted or degraded due to water ingress and need to be removed and replaced.
To accomplish a repair like this, you would need to cut out the top layer of laminate of the cockpit floor, remove damaged core. Prep. Install new core. Lay up new top laminate. Fair. Refinish with a top coat and non skid
IMO, You would need to have experience to do it sucessfully. There are lots of little details that could go wrong along the way, making it necessary to rip it out and start again. Unless you know what you’re getting into, I would NOT recommend that you take this project on.
As for the answer to the question if it’s worth doing the repair... that depends on the condition of the rest of the boat . If it needs a lot of work or parts, it’s probably not worth it, even if it’s free. There are plenty of boats out there with good trailers that are in good working condition.