The issues associated with landing a floatplane are totally different to those associated with one which is not ordinarily designed to land without its wheels.
The kind of aircraft that most people fly here may well land with some wheels extended and a propeller or two, all of which will jab into the ground on landing giving rise to the risk of a violent decelleration and/or a flip.
Landing a pair of floats or a hull on grass is not really a fair comparison.
2D