As with most issues, there is no single correct solution.

In a perfect world, the snow would land on your roof, you roof would be strong enough to support any amount that ends up on your roof. You would be warm and cozy under the additional insulation until the snow melts in spring.

In reality the widely varying conditions in various zones require that you deal with the snow in various ways.

High pitched roofs do shed snow, as long as there are no doors where the sliding snow can land on people, just let if slide off. But then you have all of that snow leaning up against the side of the structure, possibly blocking windows etc.

Metal roofs are slippery, even low pitched roofs, can allow snow to slide off. As with most avalanches, this often happens when the snow is disturbed in some way. This often happens with a door "slamming" shut, shaking the snow loose. Often while the "slammer" is still standing outside the door. This can lead to a situation that is either humorous, tragic or any place between, depending on the amount of snow or ice and the physical condition of the person under falling show or ice. Thus the "snow keepers" on metal roofs.

In other situations, depending on climate and home construction/insulation/attic ventilation, the roof surface may change from above freezing to below freezing many times while covered with snow, typically each day/night cycle. When this happens, water runs down the warm roof, under the snow. When it get to the cold edge of the roof it freezes. This creates a dam which allows water to build up and run under the shingles.

There are more situations too numerous and complex to cover here. The point is, most of the points made so far in this thread are valid. The rope technique that began the thread is a good solution for the situation where it was used. There are other good ones.