The top may be fluffy, but by the time you've dug through the top 50ft I doubt it's very fluffy anymore.
[0] - https://en.wikipedia.org/wiki/Properties_of_water#Density_of...
There is a very wide range of snow. In particular, the heavy wet stuff acts and behaves very differently from "dry" snow -- whether that's light powder on top, or compacted, but dry, snow underneath.
Wet snow is increadibly heavy, and frequently contains or mixes with ice which makes removal (blowing, ploughing, shoveling, 'dozing) far more challenging.