Helicopters: Wheelvs vs Skis

When the H-34 Choctaw came out in Vietnam, it often sank into the ground. This happened when helicopters landed on malleable surfaces and all its weight was focused on three points (the landing wheels). To resolve this, later helicopters were designed with skis. That way the weight is more distributed on both sides.
So. my question is. Why do helicopters have wheels again? Is it because they are not as heavy as older helicopters? Or modern helipads made out of harder materials.
So. my question is. Why do helicopters have wheels again? Is it because they are not as heavy as older helicopters? Or modern helipads made out of harder materials.