clearly lake town was constructed to be on the water but why? its clear they could have built beside the river and been just as profitable had more secure structures etc. so what was the point in making lake town on the lake?
Well, first, there is historical precedent for building on top of pilings including building directly over the water. But in this case, the relative proximity of the dragons of the Withered Heath might have played a part in building a town over a deep, cold lake. The Esgaroth that Thorin and Company visited was at least the second iteration of Lake-town. And the new Esgaroth was also built on the lake, a bit north of the old site.
Well, first, there is historical precedent for building on top of pilings including building directly over the water. But in this case, the relative proximity of the dragons of the Withered Heath might have played a part in building a town over a deep, cold lake. The Esgaroth that Thorin and Company visited was at least the second iteration of Lake-town. And the new Esgaroth was also built on the lake, a bit north of the old site.