Amity Today.
For the sake of this thread lets pretend the sequels didn't happen, and summer of '75 was the only time Amity had a shark problem. And ultimately they survived the financial hit, and by the next summer the story had mostly been forgotten outside the island and the people came back.
What would Amity Island be like in 2018?
I think there would be way fewer year round islanders. As more and more of them died off or moved, more rich mainlanders would buy the houses there and use them only as summer beach houses. This would drive up the property values, thus pricing out any middle class buyers. Without the year round customers, and increasing property taxes, the locally owned small business would start going away, and more chain businesses would pop up. Like the lady who talked about owning the motel would not be able to sustain it, and it would probably be a Motel 6, or Holiday Inn by now. And there would definitely be atleast 1 McDonalds there now.
So now it would be the kind of place where the average family could only afford to stay for 2 or 3 days tops.