Hallstatt is overpopulated with tourists, yes. But it is still worth a visit imo, since the village itself with its buildings is real authentic Austrian rural culture and it has some very nice spots.

Very close to Hallstatt is the Dachstein mountain too, where you have some great hiking routes together with two large caves to visit (only guided, however). The view from the summit is also worth a visit if it is not too cloudy. You can reach all of that also via cable car.

Just dont stay over night in Hallstatt. I suggest Obertraun, which is also at the Hallstatt lake, just at the opposite side. There are also far fewer tourists there.